staging: nvec: Fix comparison to NULL

Replace the use of comparison to NULL, use !<expression> instead. Checkpatch detected these issues.
Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/nvec/nvec.c

@@ -264,7 +264,7 @@ int nvec_write_async(struct nvec_chip *nvec, const unsigned char *data,
 
 	msg = nvec_msg_alloc(nvec, NVEC_MSG_TX);
 
-	if (msg == NULL)
+	if (!msg)
 		return -ENOMEM;
 
 	msg->data[0] = size;
@@ -620,7 +620,7 @@ static irqreturn_t nvec_interrupt(int irq, void *dev)
 		} else {
 			nvec->rx = nvec_msg_alloc(nvec, NVEC_MSG_RX);
 			/* Should not happen in a normal world */
-			if (unlikely(nvec->rx == NULL)) {
+			if (unlikely(!nvec->rx)) {
 				nvec->state = 0;
 				break;
 			}