serial: samsung: Fixed wrong comparison for baudclk_rate

port->baudclk_rate should be compared to the rate of port->baudclk,
because port->baudclk_rate was assigned as the rate of port->baudclk previously.
So to check that the current baudclk rate is same as previous rate,
the target of comparison sholud be the rate of port->baudclk.

Signed-off-by: Jun-Ho, Yoon <junho78.yoon@samsung.com>
Signed-off-by: Kyoungil Kim <ki0351.kim@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>