s/FD_SETFD/F_SETFD/.

Also fix an 'a'/'an' typo.

Bug: https://github.com/android/ndk/issues/1933
Test: treehugger
Change-Id: Ifd505772dce79ebd68d928c67775030e2fd98d3f
diff --git a/include/android/sharedmem.h b/include/android/sharedmem.h
index e0a8045..645fa8a 100644
--- a/include/android/sharedmem.h
+++ b/include/android/sharedmem.h
@@ -53,7 +53,7 @@
 /**
  * Create a shared memory region.
  *
- * Create shared memory region and returns an file descriptor.  The resulting file descriptor can be
+ * Create shared memory region and returns a file descriptor.  The resulting file descriptor can be
  * mmap'ed to process memory space with PROT_READ | PROT_WRITE | PROT_EXEC. Access to shared memory
  * region can be restricted with {@link ASharedMemory_setProt}.
  *
@@ -65,7 +65,7 @@
  * cmsg(3) man pages for more information.
  *
  * If you intend to share this file descriptor with a child process after
- * calling exec(3), note that you will need to use fcntl(2) with FD_SETFD
+ * calling exec(3), note that you will need to use fcntl(2) with F_SETFD
  * to clear the FD_CLOEXEC flag for this to work on all versions of Android.
  *
  * Available since API level 26.