staging: rts5208: remove unnecessary parentheses in xd.c

This commit removes unnecessary parentheses, that have been flagged
by checkpatch.pl in xd.c

Signed-off-by: Benjamin Philip <benjamin.philip495@gmail.com>
Link: https://lore.kernel.org/r/22907b882bac30e8062b0b044bcf61253768e930.1632209460.git.benjamin.philip495@gmail.com


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