dpctl: Fix memory leak in dp_exists().

Fixes: ffdcd110fa ("dpctl: Make opt_dpif_open() more general.")
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

lib/dpctl.c

@@ -202,6 +202,8 @@ dp_exists(const char *queried_dp)
 
     sset_destroy(&dpif_names);
     sset_destroy(&dpif_types);
+    free(queried_name);
+    free(queried_type);
     return found;
 }