staging: rtl8188eu: os_dep: usb_intf: Clean up tests if NULL returned on failure

Some functions like kmalloc/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 <bhaktipriya96@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/os_dep/usb_intf.c

@@ -60,7 +60,7 @@ static struct dvobj_priv *usb_dvobj_init(struct usb_interface *usb_intf)
 	struct usb_device	*pusbd;
 
 	pdvobjpriv = kzalloc(sizeof(*pdvobjpriv), GFP_KERNEL);
-	if (pdvobjpriv == NULL)
+	if (!pdvobjpriv)
 		return NULL;
 
 	pdvobjpriv->pusbintf = usb_intf;