wrong datatype caused crc check to fail almost every time

src/shellmatta_ymodem.c

@@ -371,7 +371,7 @@ shellmatta_ymodem_rcv_retcode_t shellmatta_ymodem_receive_byte(shellmatta_handle
 */
 void shellmatta_ymodem_check_packet(shellmatta_handle_t handle)
 {
-    uint8_t computedCrc = 0u;
+    uint16_t computedCrc = 0u;
     if (shellmatta_ymodem_packet.packetNumber != (0xFF - shellmatta_ymodem_packet.reversePacketNumber))
     {
         shellmatta_ymodem_nak(handle);