Staging: rtl8188eu: os_dep: osdep_service.c: Remove explicit NULL comparison

Remove explicit NULL comparison and write it in its simpler form.
Replacement done with coccinelle:

@replace_rule@
expression e;
@@

-e == NULL
+ !e

Signed-off-by: Shraddha Barke <shraddha.6596@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/os_dep/osdep_service.c

@@ -52,7 +52,7 @@ void *rtw_malloc2d(int h, int w, int size)
 	int j;
 
 	void **a = kzalloc(h*sizeof(void *) + h*w*size, GFP_KERNEL);
-	if (a == NULL) {
+	if (!a) {
 		pr_info("%s: alloc memory fail!\n", __func__);
 		return NULL;
 	}