scsi: mptfusion: Remove unnecessary parentheses

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

drivers/message/fusion/mptbase.c:338:11: warning: equality comparison
with extraneous parentheses [-Wparentheses-equality]
        if ((ioc == NULL))
             ~~~~^~~~~~~
drivers/message/fusion/mptbase.c:338:11: note: remove extraneous
parentheses around the comparison to silence this warning
        if ((ioc == NULL))
            ~    ^      ~
drivers/message/fusion/mptbase.c:338:11: note: use '=' to turn this
equality comparison into an assignment
        if ((ioc == NULL))
                 ^~
                 =
drivers/message/fusion/mptbase.c:342:12: warning: equality comparison
with extraneous parentheses [-Wparentheses-equality]
        if ((pdev == NULL))
             ~~~~~^~~~~~~
drivers/message/fusion/mptbase.c:342:12: note: remove extraneous
parentheses around the comparison to silence this warning
        if ((pdev == NULL))
            ~     ^      ~
drivers/message/fusion/mptbase.c:342:12: 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'.

Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/message/fusion/mptbase.c

@@ -335,11 +335,11 @@ static int mpt_remove_dead_ioc_func(void *arg)
 	MPT_ADAPTER *ioc = (MPT_ADAPTER *)arg;
 	struct pci_dev *pdev;
 
-	if ((ioc == NULL))
+	if (!ioc)
 		return -1;
 
 	pdev = ioc->pcidev;
-	if ((pdev == NULL))
+	if (!pdev)
 		return -1;
 
 	pci_stop_and_remove_bus_device_locked(pdev);