btrfs: sink gfp parameter to set_extent_delalloc

Callers pass GFP_NOFS and tests pass GFP_KERNEL, but using NOFS there
does not hurt. No need to pass the flags around.

Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d37997f..1a4bd19 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1962,7 +1962,7 @@
 {
 	WARN_ON((end & (PAGE_SIZE - 1)) == 0);
 	return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
-				   cached_state, GFP_NOFS);
+				   cached_state);
 }
 
 /* see btrfs_writepage_start_hook for details on why this is required */