db-ctl-base: Fix resource deallocation on error path in cmd_get().

Release resources now that we are returning to the caller on error.

Signed-off-by: Jakub Sitnicki <jkbs@redhat.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

lib/db-ctl-base.c

@@ -977,6 +977,7 @@ cmd_get(struct ctl_context *ctx)
             ctx->error = ovsdb_atom_from_string(&key, NULL, &column->type.key,
                                                 key_string, ctx->symtab);
             if (ctx->error) {
+                free(key_string);
                 return;
             }