integration/TestUpdateMemory: fix false failure

This fixes the following test failure:

> --- FAIL: TestUpdateMemory (0.53s)
>  	assertions.go:226:
>	Error Trace:	update_linux_test.go:52
>	Error:      	Not equal:
>	            	expected: int(524288000)
>	            	received: int64(524288000)

Fixes: 0f9da07b56
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

integration/container/update_linux_test.go

@@ -35,7 +35,7 @@ func TestUpdateMemory(t *testing.T) {
 
 	const (
 		setMemory     int64 = 314572800
-		setMemorySwap       = 524288000
+		setMemorySwap int64 = 524288000
 	)
 
 	_, err := client.ContainerUpdate(ctx, cID, containertypes.UpdateConfig{