staging: dgnc: remove NULL test

This NULL test is not required as iounmap will validate the argument.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/dgnc/dgnc_cls.c

@@ -1307,6 +1307,5 @@ static void cls_vpd(struct dgnc_board *brd)
 	}
 	pr_info("\n");
 
-	if (re_map_vpdbase)
-		iounmap(re_map_vpdbase);
+	iounmap(re_map_vpdbase);
 }