serial: samsung: don't check config for every character

The s3c24xx_serial_console_putchar() is _only_ ever used by
s3c24xx_serial_console_write() and is called in a loop (indirectly
through uart_console_write()).  There's no reason to call
s3c24xx_port_configured() for every iteration through the loop.  Move
it outside the loop.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>