staging: rtl8187se: bool tests don't need comparisons

This patch fixes the following coccinelle warning:

drivers/staging/rtl8187se/r8180_core.c:2217:5-40: WARNING: Comparison to bool

Signed-off-by: Teodora Baluta <teobaluta@gmail.com>
Reviewed-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>