btrfs: squash lines for simple wrapper functions

Remove unneeded variables and assignments.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 6678947..183c98f 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -2849,11 +2849,8 @@
 static struct btrfsic_dev_state *btrfsic_dev_state_lookup(
 		struct block_device *bdev)
 {
-	struct btrfsic_dev_state *ds;
-
-	ds = btrfsic_dev_state_hashtable_lookup(bdev,
-						&btrfsic_dev_state_hashtable);
-	return ds;
+	return btrfsic_dev_state_hashtable_lookup(bdev,
+						  &btrfsic_dev_state_hashtable);
 }
 
 int btrfsic_submit_bh(int op, int op_flags, struct buffer_head *bh)