kill useless checks for sb->s_op == NULL

never is...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 07a382e..e133f09 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1206,7 +1206,7 @@
 	if (!sb)
 		return 0;
 
-	if (!sb->s_op || !sb->s_op->relocate_blocks)
+	if (!sb->s_op->relocate_blocks)
 		goto out;
 
 	old_block = pkt->sector / (CD_FRAMESIZE >> 9);