cciss: use check_signature()

Use check_signature() to find a signature in the mmio address.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/cciss.c

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index bda6d12..e04c63e 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -42,8 +42,8 @@
 #include <linux/compat.h>
 #include <linux/mutex.h>
 #include <linux/bitmap.h>
+#include <linux/io.h>
 #include <asm/uaccess.h>
-#include <asm/io.h>
 
 #include <linux/dma-mapping.h>
 #include <linux/blkdev.h>
@@ -4267,10 +4267,7 @@
 
 static inline bool CISS_signature_present(ctlr_info_t *h)
 {
-	if ((readb(&h->cfgtable->Signature[0]) != 'C') ||
-	    (readb(&h->cfgtable->Signature[1]) != 'I') ||
-	    (readb(&h->cfgtable->Signature[2]) != 'S') ||
-	    (readb(&h->cfgtable->Signature[3]) != 'S')) {
+	if (!check_signature(h->cfgtable->Signature, "CISS", 4)) {
 		dev_warn(&h->pdev->dev, "not a valid CISS config table\n");
 		return false;
 	}