tty: serial: msm_serial: Remove set but unused variable 'status'

tty: serial: msm_serial: Remove set but unused variable 'status'

Fixes the following W=1 kernel build warning(s):

 drivers/tty/serial/msm_serial.c: In function ‘msm_complete_tx_dma’:
 drivers/tty/serial/msm_serial.c:429:18: warning: variable ‘status’ set but not used [-Wunused-but-set-variable]

Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Robert Love <rlove@google.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-serial@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Link: https://lore.kernel.org/r/20201104193549.4026187-21-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>