Media: Use assignment operators instead of memset.

Spotted by GCC 8 -Werror=class-memaccess.

src/add-ons/media/media-add-ons/opensound/OpenSoundDevice.cpp

@@ -189,7 +189,7 @@ status_t OpenSoundDevice::get_media_format_description_for(int fmt, media_format
 {
 	int i;
 	for (i = 0; i < count; i++)
-		memset(&desc[i], 0, sizeof(media_format_description));
+		desc[i] = media_format_description();
 	if (count < 1)
 		return 0;
 	if (fmt & AFMT_SUPPORTED_PCM) {

src/add-ons/media/media-add-ons/opensound/OpenSoundNode.cpp

@@ -345,7 +345,7 @@ OpenSoundNode::OpenSoundNode(BMediaAddOn* addon, const char* name,
 	// initialize our preferred format object
 	// TODO: this should go away! should use engine's preferred for each afmt.
 #if 1
-	memset(&fPreferredFormat, 0, sizeof(fPreferredFormat));
+	fPreferredFormat = media_format();
 		// set everything to wildcard first
 	fPreferredFormat.type = B_MEDIA_RAW_AUDIO;
 	fPreferredFormat.u.raw_audio = media_multi_audio_format::wildcard;

src/apps/cortex/TransportView/TransportView.cpp

@@ -1027,7 +1027,7 @@ void TransportView::_updateTimeSource() {
 		if(err < B_OK)
 			continue;
 
-		memcpy(&itemNode, data, sizeof(media_node));
+		itemNode = *((media_node*)data);
 		if(itemNode != tsNode)
 			continue;
 
@@ -1149,7 +1149,7 @@ void TransportView::_timeSourceDeleted(
 		if(err < B_OK)
 			continue;
 
-		memcpy(&itemNode, data, sizeof(media_node));
+		itemNode = *((media_node*)data);
 		if(itemNode.node != id)
 			continue;
 

src/apps/cortex/addons/LoggingConsumer/LoggingConsumer.cpp

@@ -465,7 +465,7 @@ LoggingConsumer::Disconnected(
 	mLogger->Log(LOG_DISCONNECTED, logMsg);
 
 	// wipe out our input record
-	memset(&mInput, 0, sizeof(mInput));
+	mInput = media_input();
 }
 
 status_t

src/preferences/media/MediaViews.cpp

@@ -432,7 +432,7 @@ AudioSettingsView::_FillChannelMenu(const dormant_node_info* nodeInfo)
 
 			for (int32 i = 0; i < inputCount; i++) {
 				media_input* input = new media_input();
-				memcpy(input, &inputs[i], sizeof(*input));
+				*input = inputs[i];
 				ChannelMenuItem* channelItem = new ChannelMenuItem(input,
 					new BMessage(message));
 				fChannelMenu->AddItem(channelItem);