daemon: fix leak after listing all volumes

CVE-2013-1962

remoteDispatchStoragePoolListAllVolumes wasn't freeing the pool.
The pool also held a reference to the connection, preventing it from
getting freed and closing the netcf interface driver, which held two
sockets open.
(cherry picked from commit ca697e90)

daemon/remote.c

@@ -4233,6 +4233,8 @@ cleanup:
             virStorageVolFree(vols[i]);
         VIR_FREE(vols);
     }
+    if (pool)
+        virStoragePoolFree(pool);
     return rv;
 }