Unix CM: Don't check if var is 0, then zero it

Unix CM: Don't check if var is 0, then zero it

There's a couple of places in afs_daemons.c where we do:

    if (code != 0)
        return;
    code = 0;

The final line is obviously redundant, and makes clang sulk at us.
So, remove it.

Caught by clang-analyzer

Change-Id: Ic55edf1b05f3f45eb1f0cecdb3c2318e6f7bd0ec
Reviewed-on: http://gerrit.openafs.org/9154
Reviewed-by: Marc Dionne <marc.c.dionne@gmail.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>