ext4: move __func__ into a macro for ext4_warning, ext4_error

Just a pet peeve of mine; we had a mishash of calls with either __func__
or "function_name" and the latter tends to get out of sync.

I think it's easier to just hide the __func__ in a macro, and it'll
be consistent from then on.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 9dc93168..0e0bef3 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -83,7 +83,7 @@
 		error_msg = "inode out of bounds";
 
 	if (error_msg != NULL)
-		ext4_error(dir->i_sb, function,
+		__ext4_error(dir->i_sb, function,
 			"bad entry in directory #%lu: %s - "
 			"offset=%u, inode=%u, rec_len=%d, name_len=%d",
 			dir->i_ino, error_msg, offset,
@@ -150,7 +150,7 @@
 		 */
 		if (!bh) {
 			if (!dir_has_error) {
-				ext4_error(sb, __func__, "directory #%lu "
+				ext4_error(sb, "directory #%lu "
 					   "contains a hole at offset %Lu",
 					   inode->i_ino,
 					   (unsigned long long) filp->f_pos);