nfsd4: fix xdr4 inclusion of escaped char

Fix a bug where nfsd4_encode_components_esc() includes the esc_end char as
an additional string encoding.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Cc: stable@vger.kernel.org
Fixes: e7a0444a "nfsd: add IPv6 addr escaping to fs_location hosts"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

(cherry picked from commit 5a64e569)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

fs/nfsd/nfs4xdr.c

@@ -1766,6 +1766,9 @@ static __be32 nfsd4_encode_components_esc(char sep, char *components,
 		}
 		else
 			end++;
+		if (found_esc)
+			end = next;
+
 		str = end;
 	}
 	*pp = p;