test: media_device: Add test for acquire() and release()

The interfaces MediaDevice::{open,close}() are about to be made private,
replace them with a test of MediaDevice::{acquire,release}() instead.
The new test will implicitly tests the open() and close() methods as
they are about to be move inside acquire() and release() which will
remain public.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

test/media_device/media_device_print_test.cpp

@@ -113,17 +113,6 @@ int MediaDevicePrintTest::testMediaDevice(const string deviceNode)
 	MediaDevice dev(deviceNode);
 	int ret;
 
-	/* Fuzzy open/close sequence. */
-	ret = dev.open();
-	if (ret)
-		return ret;
-
-	ret = dev.open();
-	if (!ret)
-		return ret;
-
-	dev.close();
-
 	ret = dev.populate();
 	if (ret)
 		return ret;