Btrfs: consolidate btrfs_error() to btrfs_std_error()

btrfs_error() and btrfs_std_error() does the same thing
and calls _btrfs_std_error(), so consolidate them together.
And the main motivation is that btrfs_error() is closely
named with btrfs_err(), one handles error action the other
is to log the error, so don't closely name them.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Suggested-by: David Sterba <dsterba@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 360a728..6d90851 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -283,7 +283,7 @@
 			trans = btrfs_join_transaction(tree_root);
 			if (IS_ERR(trans)) {
 				err = PTR_ERR(trans);
-				btrfs_error(tree_root->fs_info, err,
+				btrfs_std_error(tree_root->fs_info, err,
 					    "Failed to start trans to delete "
 					    "orphan item");
 				break;
@@ -292,7 +292,7 @@
 						    root_key.objectid);
 			btrfs_end_transaction(trans, tree_root);
 			if (err) {
-				btrfs_error(tree_root->fs_info, err,
+				btrfs_std_error(tree_root->fs_info, err,
 					    "Failed to delete root orphan "
 					    "item");
 				break;