btrfs: drop unused parameter from extent_map_tree_init

the GFP flags are not stored anywhere and all allocations are done via
alloc_extent_map(GFP_NOFS).

Signed-off-by: David Sterba <dsterba@suse.cz>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3c98164..f54c015 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6785,7 +6785,7 @@
 	ei->force_compress = BTRFS_COMPRESS_NONE;
 
 	inode = &ei->vfs_inode;
-	extent_map_tree_init(&ei->extent_tree, GFP_NOFS);
+	extent_map_tree_init(&ei->extent_tree);
 	extent_io_tree_init(&ei->io_tree, &inode->i_data);
 	extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
 	mutex_init(&ei->log_mutex);