[SCSI] qlogicpti: add missing parentheses

`+' has a higher precedence than `?' so the condition always
evaluates to true and this is preprocessed to `7*((ql) - 1)'
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/qlogicpti.h

@@ -43,7 +43,7 @@
  * determined for each queue request anew.
  */
 #define QLOGICPTI_REQ_QUEUE_LEN	255	/* must be power of two - 1 */
-#define QLOGICPTI_MAX_SG(ql)	(4 + ((ql) > 0) ? 7*((ql) - 1) : 0)
+#define QLOGICPTI_MAX_SG(ql)	(4 + (((ql) > 0) ? 7*((ql) - 1) : 0))
 
 /* mailbox command complete status codes */
 #define MBOX_COMMAND_COMPLETE		0x4000