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/extents.c b/fs/ext4/extents.c
index 5461615..bd80891 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -440,7 +440,7 @@
 	return 0;
 
 corrupted:
-	ext4_error(inode->i_sb, function,
+	__ext4_error(inode->i_sb, function,
 			"bad header/extent in inode #%lu: %s - magic %x, "
 			"entries %u, max %u(%u), depth %u(%u)",
 			inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic),
@@ -1538,8 +1538,9 @@
 		merge_done = 1;
 		WARN_ON(eh->eh_entries == 0);
 		if (!eh->eh_entries)
-			ext4_error(inode->i_sb, "ext4_ext_try_to_merge",
-			   "inode#%lu, eh->eh_entries = 0!", inode->i_ino);
+			ext4_error(inode->i_sb,
+				   "inode#%lu, eh->eh_entries = 0!",
+				   inode->i_ino);
 	}
 
 	return merge_done;
@@ -3238,7 +3239,7 @@
 	 * this is why assert can't be put in ext4_ext_find_extent()
 	 */
 	if (path[depth].p_ext == NULL && depth != 0) {
-		ext4_error(inode->i_sb, __func__, "bad extent address "
+		ext4_error(inode->i_sb, "bad extent address "
 			   "inode: %lu, iblock: %d, depth: %d",
 			   inode->i_ino, iblock, depth);
 		err = -EIO;