btrfs: drop gfp parameter from alloc_extent_map

pass GFP_NOFS directly to kmem_cache_alloc

Signed-off-by: David Sterba <dsterba@suse.cz>
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index f3edf45..2097a88 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2870,7 +2870,7 @@
 	struct extent_map *em;
 	int ret = 0;
 
-	em = alloc_extent_map(GFP_NOFS);
+	em = alloc_extent_map();
 	if (!em)
 		return -ENOMEM;