staging: rtl8712: mlme_linux: Clean up tests if NULL returned on failure

Some functions like kzalloc return NULL on failure.
When NULL represents failure, !x is commonly used.

This was done using Coccinelle:

@@
expression *e;
identifier l1;
@@

e = \(kmalloc\|kzalloc\|kcalloc\|devm_kzalloc\)(...);
...
- e == NULL
+ !e

Signed-off-by: Bhaktipriya Shridhar <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/rtl8712/mlme_linux.c

···
 	buff = NULL;
 	if (authmode == _WPA_IE_ID_) {
 		buff = kzalloc(IW_CUSTOM_MAX, GFP_ATOMIC);
-		if (buff == NULL)
+		if (!buff)
 			return;
 		p = buff;
 		p += sprintf(p, "ASSOCINFO(ReqIEs=");