btrfs: sink unlock_extent parameter gfp_flags

All callers pass either GFP_NOFS or GFP_KERNEL now, so we can sink the
parameter to the function, though we lose some of the slightly better
semantics of GFP_KERNEL in some places, it's worth cleaning up the
callchains.

Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 8780945..930c1ea 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1648,7 +1648,7 @@ STATIC u64 find_lock_delalloc_range(struct inode *inode,
 			     EXTENT_DELALLOC, 1, cached_state);
 	if (!ret) {
 		unlock_extent_cached(tree, delalloc_start, delalloc_end,
-				     &cached_state, GFP_NOFS);
+				     &cached_state);
 		__unlock_for_delalloc(inode, locked_page,
 			      delalloc_start, delalloc_end);
 		cond_resched();
@@ -2941,8 +2941,7 @@ static int __do_readpage(struct extent_io_tree *tree,
 			set_extent_uptodate(tree, cur, cur + iosize - 1,
 					    &cached, GFP_NOFS);
 			unlock_extent_cached(tree, cur,
-					     cur + iosize - 1,
-					     &cached, GFP_NOFS);
+					     cur + iosize - 1, &cached);
 			break;
 		}
 		em = __get_extent_map(inode, page, pg_offset, cur,
@@ -3035,8 +3034,7 @@ static int __do_readpage(struct extent_io_tree *tree,
 			set_extent_uptodate(tree, cur, cur + iosize - 1,
 					    &cached, GFP_NOFS);
 			unlock_extent_cached(tree, cur,
-					     cur + iosize - 1,
-					     &cached, GFP_NOFS);
+					     cur + iosize - 1, &cached);
 			cur = cur + iosize;
 			pg_offset += iosize;
 			continue;
@@ -4621,7 +4619,7 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 out:
 	btrfs_free_path(path);
 	unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
-			     &cached_state, GFP_NOFS);
+			     &cached_state);
 	return ret;
 }