nfsd: use passed cache_detail pointer expkey_parse()

Using of hard-coded svc_expkey_cache pointer in expkey_parse() looks redundant.
Moreover, global cache will be replaced with per-net instance soon.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 8e9689a..71c5ce3 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -163,7 +163,7 @@
 	cache_flush();
  out:
 	if (ek)
-		cache_put(&ek->h, &svc_expkey_cache);
+		cache_put(&ek->h, cd);
 	if (dom)
 		auth_domain_put(dom);
 	kfree(buf);