Reinstate "GFS2: free disk inode which is deleted by remote node -V2"

It turns out that reverting commit 970343cd ("GFS2: free disk inode
which is deleted by remote node -V2") causes a regression related to
evicting inodes that were unlinked on a different cluster node.

We could also have simply added a call to d_mark_dontcache() to function
gfs2_try_evict(), but the original pre-revert code is better tested and
proven.

This reverts commit 445cb127

.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>