scsi: mpt3sas: Remove unnecessary parentheses and simplify null checks

Clang warns when multiple pairs of parentheses are used for a single
conditional statement.

drivers/scsi/mpt3sas/mpt3sas_base.c:535:11: warning: equality comparison
with extraneous parentheses [-Wparentheses-equality]
        if ((ioc == NULL))
             ~~~~^~~~~~~
drivers/scsi/mpt3sas/mpt3sas_base.c:535:11: note: remove extraneous
parentheses around the comparison to silence this warning
        if ((ioc == NULL))
            ~    ^      ~
drivers/scsi/mpt3sas/mpt3sas_base.c:535:11: note: use '=' to turn this
equality comparison into an assignment
        if ((ioc == NULL))
                 ^~
                 =
drivers/scsi/mpt3sas/mpt3sas_base.c:539:12: warning: equality comparison
with extraneous parentheses [-Wparentheses-equality]
        if ((pdev == NULL))
             ~~~~~^~~~~~~
drivers/scsi/mpt3sas/mpt3sas_base.c:539:12: note: remove extraneous
parentheses around the comparison to silence this warning
        if ((pdev == NULL))
            ~     ^      ~
drivers/scsi/mpt3sas/mpt3sas_base.c:539:12: note: use '=' to turn this
equality comparison into an assignment
        if ((pdev == NULL))
                  ^~
                  =
2 warnings generated.

Remove them and while we're at it, simplify the NULL checks as '!var' is
used more than 'var == NULL'.
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpt3sas/mpt3sas_base.c

@@ -530,11 +530,11 @@ static int mpt3sas_remove_dead_ioc_func(void *arg)
 	struct MPT3SAS_ADAPTER *ioc = (struct MPT3SAS_ADAPTER *)arg;
 	struct pci_dev *pdev;
 
-	if ((ioc == NULL))
+	if (!ioc)
 		return -1;
 
 	pdev = ioc->pdev;
-	if ((pdev == NULL))
+	if (!pdev)
 		return -1;
 	pci_stop_and_remove_bus_device_locked(pdev);
 	return 0;