Staging: speakup: &&/|| confusion in silent_store()

Fix test: the branch is always taken.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>