Staging: bcm: mocro expansion bug

The WIMAX_MAX_MTU macro is used in drivers/staging/bcm/CmHost.c like
this:

    if (Adapter->PackInfo[uiSearchRuleIndex].uiMaxBucketSize < WIMAX_MAX_MTU * 8)

The multiplication by eight has precedence over the addition so the
macro needs parenthesis to work.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>