staging: rtl8188eu: os_dep: Remove NULL test before vfree

vfree frees the virtually continuous memory area starting at addr.
If addr is NULL, no operation is performed. So NULL test is not needed
before vfree.

This was done using Coccinelle:

@@
expression x;
@@
-if (x != NULL)
    vfree(x);

@@
expression x;
@@

-if (x != NULL) {
vfree(x);
x = NULL;
-}
Signed-off-by: NBhaktipriya Shridhar <bhaktipriya96@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/os_dep/usb_intf.c

@@ -442,7 +442,7 @@ static struct adapter *rtw_usb_if1_init(struct dvobj_priv *dvobj,
 	if (status != _SUCCESS) {
 		if (pnetdev)
 			rtw_free_netdev(pnetdev);
-		else if (padapter)
+		else
 			vfree(padapter);
 		padapter = NULL;
 	}