salvager: Fix in-memory invalid linktable counts

When we have a nonexistant or invalid linktable, we manually set all
of the linkcounts to 1, since we're recreating the link table from
scratch. However, we also have a linkCount count in our in-memory
allInodes array, which could be populated by garbage if we had a
garbage linktable. So make sure to set our in-memory linkCount to 1
for each inode, so we don't use garbage linkcount data.

Change-Id: I8f4873e12f70f81ee6f2c764957e77136b0a385e
Reviewed-on: http://gerrit.openafs.org/10312
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>