[sanitizer] found a bug by code inspection: CHECK(a=b) instead of CHECK(a==b). Was puzzled why lint did not catch it. Turns out this check was disabled for asan source. fix all cases and enable the check

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@178872 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/asan/asan_thread.cc b/lib/asan/asan_thread.cc
index 8cda544..64d70d6 100644
--- a/lib/asan/asan_thread.cc
+++ b/lib/asan/asan_thread.cc
@@ -129,7 +129,7 @@
     // start_routine_ == 0 if we're on the main thread or on one of the
     // OS X libdispatch worker threads. But nobody is supposed to call
     // ThreadStart() for the worker threads.
-    CHECK(tid() == 0);
+    CHECK_EQ(tid(), 0);
     return 0;
   }