vol/salvaged.c: Remove unused variable

vol/salvaged.c: Remove unused variable

It was incremented from an uninitialized value, which caused a build
error on the OS X 10.9 buildslave.  Since it's unused, just remove
it entirely.

Change-Id: I845e9139ffd27ba7bf4e010cf4e5625658125486
Reviewed-on: http://gerrit.openafs.org/10698
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>