USB: free memory when writing fails in usb/serial/mos7840.c

Free buffer when writing ZLP_REG5 failed

Signed-off-by: Roel Kluin <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/serial/mos7840.c

···
 	status = mos7840_set_reg_sync(serial->port[0], ZLP_REG5, Data);
 	if (status < 0) {
 		dbg("Writing ZLP_REG5 failed status-0x%x\n", status);
-		return -1;
+		goto error;
 	} else
 		dbg("ZLP_REG5 Writing success status%d\n", status);