tty: synclink: remove unneeded test

We reach this point of code after a test of 'info->port.tty->hw_stopped',
we do not need to test for 'info->port.tty' as it is obvious that
info->port.tty is not NULL now, we have already dereferenced it.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>