staging: rtl8712: Fix multiple line dereference

Reported by checkpatch:

WARNING: Avoid multiple line dereference

Signed-off-by: Alaa Mohamed <eng.alaamohamedsoliman.am@gmail.com>
Link: https://lore.kernel.org/r/20220404210010.9795-1-eng.alaamohamedsoliman.am@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>