tty: serial: fsl_lpuart: remove the count initialization as it is not needed

No need to initialize the count variable in lpuart_copy_rx_to_tty(),
so let's remove it here.

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20220418021844.29591-1-sherry.sun@nxp.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>