Media Kit: Fix/appease various GCC 11 warnings.

src/kits/media/MediaRoster.cpp

@@ -1561,7 +1561,7 @@ BMediaRoster::PrerollNode(const media_node& node)
 	if (IS_INVALID_NODE(node))
 		return B_MEDIA_BAD_NODE;
 
-	char dummy;
+	char dummy = 0;
 	return write_port(node.port, NODE_PREROLL, &dummy, sizeof(dummy));
 }
 

src/kits/media/experimental/MediaClient.cpp

@@ -581,12 +581,12 @@ BMediaClient::_ReleaseConnection(BMediaConnection* conn)
 		return B_ERROR;
 
 	if (conn->Connection().IsInput()) {
-		InputReleaser obj = InputReleaser(dynamic_cast<BMediaInput*>(conn));
+		InputReleaser obj(dynamic_cast<BMediaInput*>(conn));
-		fInputs.RemoveItem(&obj);
+		fInputs.RemoveItem(&obj, false);
 		return B_OK;
 	} else {
-		OutputReleaser obj = OutputReleaser(dynamic_cast<BMediaOutput*>(conn));
+		OutputReleaser obj(dynamic_cast<BMediaOutput*>(conn));
-		fOutputs.RemoveItem(&obj);
+		fOutputs.RemoveItem(&obj, false);
 		return B_OK;
 	}
 

src/servers/media_addon/MediaAddonServer.cpp

@@ -549,7 +549,7 @@ MediaAddonServer::_AddOnAdded(const char* path, ino_t fileNode)
 		// put file's inode and addon's id into map
 		fFileMap.insert(std::make_pair(fileNode, id));
 
-		AddOnInfo info;
+		AddOnInfo info = {};
 		fInfoMap.insert(std::make_pair(id, info));
 	} catch (std::bad_alloc& exception) {
 		fFileMap.erase(fileNode);