Clean up InputChannel file descriptor data type.

File descriptors are ints.

Change-Id: Ie36733bf36ddfeaa9a09ef6ebd7bd2f1788f5d27
diff --git a/services/input/InputDispatcher.cpp b/services/input/InputDispatcher.cpp
index d4e59d1..e6e28df 100644
--- a/services/input/InputDispatcher.cpp
+++ b/services/input/InputDispatcher.cpp
@@ -3105,7 +3105,7 @@
 
         sp<Connection> connection = new Connection(inputChannel, inputWindowHandle, monitor);
 
-        int32_t fd = inputChannel->getFd();
+        int fd = inputChannel->getFd();
         mConnectionsByFd.add(fd, connection);
 
         if (monitor) {