Staging: gdm724x: fix space before comma coding style issue in gdm_mux.c

This is a patch to the gdm_mux.c file that fixes a space before comma
coding style issue found by the checkpatch.pl tool.

Signed-off-by: Robert Nachlinger <robert.nachlinger@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>