4795bb37 "nfsd: break lease on unlink,
link, and rename", only broke the lease on the file that was being
renamed, and didn't handle the case where the target path refers to an
already-existing file that will be unlinked by a rename--in that case
the target file should have any leases broken as well.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>