net: irda: fix wait_until_sent poll timeout

commit 2c3fbe3cf28fbd7001545a92a83b4f8acfd9fa36 upstream.

In case an infinite timeout (0) is requested, the irda wait_until_sent
implementation would use a zero poll timeout rather than the default
200ms.

Note that wait_until_sent is currently never called with a 0-timeout
argument due to a bug in tty_wait_until_sent.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>