NFSD: Using exp_get for export getting

Don't using cache_get besides export.h, using exp_get for export.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 7498099..df7cf61 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -189,8 +189,7 @@
 	dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
 
 	dparent = fhp->fh_dentry;
-	exp  = fhp->fh_export;
-	exp_get(exp);
+	exp = exp_get(fhp->fh_export);
 
 	/* Lookup the name, but don't follow links */
 	if (isdotent(name, len)) {