Revert semantic changes for fd_notify_on_*
diff --git a/src/core/lib/iomgr/buffer_list.h b/src/core/lib/iomgr/buffer_list.h
index 0f66dcc..cbbf50a 100644
--- a/src/core/lib/iomgr/buffer_list.h
+++ b/src/core/lib/iomgr/buffer_list.h
@@ -31,6 +31,8 @@
 
 namespace grpc_core {
 struct Timestamps {
+  /* TODO(yashykt): This would also need to store OPTSTAT once support is added
+   */
   gpr_timespec sendmsg_time;
   gpr_timespec scheduled_time;
   gpr_timespec sent_time;
diff --git a/src/core/lib/iomgr/ev_epoll1_linux.cc b/src/core/lib/iomgr/ev_epoll1_linux.cc
index e8ee5c4..86a0243 100644
--- a/src/core/lib/iomgr/ev_epoll1_linux.cc
+++ b/src/core/lib/iomgr/ev_epoll1_linux.cc
@@ -386,27 +386,15 @@
 }
 
 static void fd_notify_on_read(grpc_fd* fd, grpc_closure* closure) {
-  if (closure != nullptr) {
-    fd->read_closure->NotifyOn(closure);
-  } else {
-    fd->read_closure->SetReady();
-  }
+  fd->read_closure->NotifyOn(closure);
 }
 
 static void fd_notify_on_write(grpc_fd* fd, grpc_closure* closure) {
-  if (closure != nullptr) {
-    fd->write_closure->NotifyOn(closure);
-  } else {
-    fd->write_closure->SetReady();
-  }
+  fd->write_closure->NotifyOn(closure);
 }
 
 static void fd_notify_on_error(grpc_fd* fd, grpc_closure* closure) {
-  if (closure != nullptr) {
-    fd->error_closure->NotifyOn(closure);
-  } else {
-    fd->error_closure->SetReady();
-  }
+  fd->error_closure->NotifyOn(closure);
 }
 
 static void fd_become_readable(grpc_fd* fd, grpc_pollset* notifier) {
diff --git a/src/core/lib/iomgr/ev_epollex_linux.cc b/src/core/lib/iomgr/ev_epollex_linux.cc
index b17aa90..7b36841 100644
--- a/src/core/lib/iomgr/ev_epollex_linux.cc
+++ b/src/core/lib/iomgr/ev_epollex_linux.cc
@@ -539,27 +539,15 @@
 }
 
 static void fd_notify_on_read(grpc_fd* fd, grpc_closure* closure) {
-  if (closure != nullptr) {
-    fd->read_closure->NotifyOn(closure);
-  } else {
-    fd->read_closure->SetReady();
-  }
+  fd->read_closure->NotifyOn(closure);
 }
 
 static void fd_notify_on_write(grpc_fd* fd, grpc_closure* closure) {
-  if (closure != nullptr) {
-    fd->write_closure->NotifyOn(closure);
-  } else {
-    fd->write_closure->SetReady();
-  }
+  fd->write_closure->NotifyOn(closure);
 }
 
 static void fd_notify_on_error(grpc_fd* fd, grpc_closure* closure) {
-  if (closure != nullptr) {
-    fd->error_closure->NotifyOn(closure);
-  } else {
-    fd->error_closure->SetReady();
-  }
+  fd->error_closure->NotifyOn(closure);
 }
 
 /*******************************************************************************
diff --git a/src/core/lib/iomgr/ev_epollsig_linux.cc b/src/core/lib/iomgr/ev_epollsig_linux.cc
index 7bdfa22..2189801 100644
--- a/src/core/lib/iomgr/ev_epollsig_linux.cc
+++ b/src/core/lib/iomgr/ev_epollsig_linux.cc
@@ -947,27 +947,15 @@
 }
 
 static void fd_notify_on_read(grpc_fd* fd, grpc_closure* closure) {
-  if (closure != nullptr) {
-    fd->read_closure->NotifyOn(closure);
-  } else {
-    fd->read_closure->SetReady();
-  }
+  fd->read_closure->NotifyOn(closure);
 }
 
 static void fd_notify_on_write(grpc_fd* fd, grpc_closure* closure) {
-  if (closure != nullptr) {
-    fd->write_closure->NotifyOn(closure);
-  } else {
-    fd->write_closure->SetReady();
-  }
+  fd->write_closure->NotifyOn(closure);
 }
 
 static void fd_notify_on_error(grpc_fd* fd, grpc_closure* closure) {
-  if (closure != nullptr) {
-    fd->error_closure->NotifyOn(closure);
-  } else {
-    fd->error_closure->SetReady();
-  }
+  fd->error_closure->NotifyOn(closure);
 }
 
 /*******************************************************************************
diff --git a/src/core/lib/iomgr/internal_errqueue.cc b/src/core/lib/iomgr/internal_errqueue.cc
index 3f3da66..8823737 100644
--- a/src/core/lib/iomgr/internal_errqueue.cc
+++ b/src/core/lib/iomgr/internal_errqueue.cc
@@ -30,7 +30,7 @@
 
 bool kernel_supports_errqueue() {
 #ifdef LINUX_VERSION_CODE
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(4, 0, 0)
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 0, 0)
   return true;
 #endif /* LINUX_VERSION_CODE <= KERNEL_VERSION(4, 0, 0) */
 #endif /* LINUX_VERSION_CODE */