Unix CM: Update AFS_STATS_NUM_FS_RPC_OPS

There are actually 30 elements in the AFS_STATS_FS array. When the
ResidencyRpcs counter was added, the total number of operations
wasn't updated.

Fix this so that it is correct, although this still remains rather
fragile.

Change-Id: I92a0d2bf3741bc7aaeae837d6dcbcd30616e17ae
Reviewed-on: http://gerrit.openafs.org/9313
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>