logger: avoid memset, use braced initializer instead

src/modules/logger/logger.cpp

@@ -1777,9 +1777,8 @@ void Logger::write_header()
 	write_message(&header, sizeof(header));
 
 	// write the Flags message: this MUST be written right after the ulog header
-	ulog_message_flag_bits_s flag_bits;
+	ulog_message_flag_bits_s flag_bits{};
 
-	memset(&flag_bits, 0, sizeof(flag_bits));
 	flag_bits.msg_size = sizeof(flag_bits) - ULOG_MSG_HEADER_LEN;
 	flag_bits.msg_type = static_cast<uint8_t>(ULogMessageType::FLAG_BITS);