dpif-netdev: fix memory leak in dpcls subtable set command

This patch fixes a memory leak when the command
"dpif-netdev/subtable-lookup-prio-set" is run, the pmd_list
required to iterate the PMD threads was not being freed.
This issue was identified by a static analysis tool.

Fixes: 3d018c3 ("dpif-netdev: Add subtable lookup prio set command.")
Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
Acked-by: Kevin Traynor <ktraynor@redhat.com>
Signed-off-by: Ian Stokes <ian.stokes@intel.com>

lib/dpif-netdev.c

@@ -994,6 +994,7 @@ dpif_netdev_subtable_lookup_set(struct unixctl_conn *conn, int argc OVS_UNUSED,
 
         /* release port mutex before netdev mutex. */
         ovs_mutex_unlock(&dp->port_mutex);
+        free(pmd_list);
     }
     ovs_mutex_unlock(&dp_netdev_mutex);