Btrfs: Use ERR_CAST helpers

Use ERR_CAST(x) rather than ERR_PTR(PTR_ERR(x)).  The former makes more
clear what is the purpose of the operation, which otherwise looks like a
no-op.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
type T;
T x;
identifier f;
@@

T f (...) { <+...
- ERR_PTR(PTR_ERR(x))
+ x
 ...+> }

@@
expression x;
@@

- ERR_PTR(PTR_ERR(x))
+ ERR_CAST(x)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 454ca52..23cb8da 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -335,7 +335,7 @@ struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
 		goto out;
 	}
 	if (IS_ERR(rb_node)) {
-		em = ERR_PTR(PTR_ERR(rb_node));
+		em = ERR_CAST(rb_node);
 		goto out;
 	}
 	em = rb_entry(rb_node, struct extent_map, rb_node);
@@ -384,7 +384,7 @@ struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
 		goto out;
 	}
 	if (IS_ERR(rb_node)) {
-		em = ERR_PTR(PTR_ERR(rb_node));
+		em = ERR_CAST(rb_node);
 		goto out;
 	}
 	em = rb_entry(rb_node, struct extent_map, rb_node);