tvolser: Link libafsrpc after libusd

tvolser: Link libafsrpc after libusd

libusd can contain a reference to AssertionFailed, which is in
libafsrpc. So link libafsrpc after libusd, so it gets resolved when
building e.g. vos.

Reviewed-on: http://gerrit.openafs.org/3477
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit ddc4057ce786ebbe75b8b2c971b1013187062f1f)

Change-Id: I1a4325364e650fb82600e0c2c6ec64fd42912b23
Reviewed-on: http://gerrit.openafs.org/3796
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>