greybus: es2: fix arpc response-allocation error handling

The wrong pointer was checked for allocation failures when allocating
the ARPC response buffer, something which would lead to allocation
failures going undetected.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/es2.c

@@ -1100,7 +1100,7 @@ static struct arpc *arpc_alloc(void *payload, u16 size, u8 type)
 		goto err_free_rpc;
 
 	rpc->resp = kzalloc(sizeof(*rpc->resp), GFP_KERNEL);
-	if (!rpc->req)
+	if (!rpc->resp)
 		goto err_free_req;
 
 	rpc->req->type = type;