tm: rest the pointer of hash table after free to avoid double free on false start

(cherry picked from commit 7728464362af67eff4dc105f16a1d42c72407cca)

modules/tm/h_table.c

@@ -444,6 +444,7 @@ void free_hash_table(  )
 			}
 		}
 		shm_free(_tm_table);
+		_tm_table = 0;
 	}
 }