nfsd: Fix inconsistent assignment

Dereferenced pointer "dentry" without checking and assigned to inode
in the declaration.

(We could just delete the NULL checks that follow instead, as we never
get to the encode function in this particular case.  But it takes a
little detective work to verify that fact, so it's probably safer to
leave the checks in place.)

Cc: Steve French <smfltc@us.ibm.com>
Signed-off-by: NPrasad V Potluri <pvp@us.ibm.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/nfs2acl.c

@@ -221,12 +221,17 @@ static int nfsaclsvc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p,
 		struct nfsd3_getaclres *resp)
 {
 	struct dentry *dentry = resp->fh.fh_dentry;
-	struct inode *inode = dentry->d_inode;
+	struct inode *inode;
 	struct kvec *head = rqstp->rq_res.head;
 	unsigned int base;
 	int n;
 	int w;
 
+	/*
+	 * Since this is version 2, the check for nfserr in
+	 * nfsd_dispatch actually ensures the following cannot happen.
+	 * However, it seems fragile to depend on that.
+	 */
 	if (dentry == NULL || dentry->d_inode == NULL)
 		return 0;
 	inode = dentry->d_inode;