tty: serial: msm: remove braces {} in msm_serial.c

fixed below checkpatch.pl warning:

WARNING: braces {} are not necessary for any arm of this statement

Signed-off-by: Kiran Padwal <kiran.padwal@smartplayin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>