fileserver & friends: Don't cast from malloc()

fileserver & friends: Don't cast from malloc()

malloc() returns a (void *) on all of our current platforms. So,
don't bother casting the return value before assigning it - it's
unecessary noise.

Change-Id: I9d41f2f1aee03d9317b4c5780fb00e13d30b0821
Reviewed-on: http://gerrit.openafs.org/7461
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>