ext4: optimize ext4_check_dir_entry() with unlikely() annotations

This function gets called a lot for large directories, and the answer
is almost always "no, no, there's no problem".  This means using
unlikely() is a good thing.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 17baecb..49f1cea 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1639,7 +1639,8 @@
 				  struct ext4_dir_entry_2 *,
 				  struct buffer_head *, unsigned int);
 #define ext4_check_dir_entry(dir, de, bh, offset) \
-	__ext4_check_dir_entry(__func__, __LINE__, (dir), (de), (bh), (offset))
+	unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (de), \
+					(bh), (offset)))
 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
 				    __u32 minor_hash,
 				    struct ext4_dir_entry_2 *dirent);