btrfs: sink gfp parameter to convert_extent_bit

Single caller passes GFP_NOFS. We can get rid of the
gfpflags_allow_blocking checks as NOFS can block but does not recurse to
filesystem through reclaim.

Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 94b3764..9c1f160 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -287,7 +287,7 @@
 
 int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 		       unsigned bits, unsigned clear_bits,
-		       struct extent_state **cached_state, gfp_t mask);
+		       struct extent_state **cached_state);
 
 static inline int set_extent_delalloc(struct extent_io_tree *tree, u64 start,
 		u64 end, struct extent_state **cached_state)