staging: unisys: remove extra parens from uislib_enable_channel_interrupts()

Get rid of the extra parenthesis in uislib_enable_channel_interrupts().

Signed-off-by: Bryan Thompson <bryan.thompson@unisys.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>