output-filedata: fix memleak

This fixes:

Direct leak of 31792 byte(s) in 3974 object(s) allocated from:
    #0 0x4c396b in malloc (/opt/suricata-asan/bin/suricata+0x4c396b)
    #1 0xd86ce2 in OutputFiledataLogThreadInit /home/pmanev/sandnet-qa/stage/oisf/src/output-filedata.c:308:34
    #2 0x106c255 in TmThreadsSlotPktAcqLoop /home/pmanev/sandnet-qa/stage/oisf/src/tm-threads.c:295:17
    #3 0x7fbc9fcb3181 in start_thread /build/eglibc-3GlaMS/eglibc-2.19/nptl/pthread_create.c:312

src/output-filedata.c

@@ -434,6 +434,8 @@ static TmEcode OutputFiledataLogThreadDeinit(ThreadVars *tv, void *thread_data)
         g_waldo_deinit = 1;
     }
     SCMutexUnlock(&g_waldo_mutex);
+
+    SCFree(op_thread_data);
     return TM_ECODE_OK;
 }