source-pcap-file: fix stats not being reset

Fix for redmine #1737. Clears stats between each scanned PCAP instead of just 
on load in Unix socket mode.

src/source-pcap-file.c

@@ -108,8 +108,6 @@ TmEcode DecodePcapFileThreadDeinit(ThreadVars *tv, void *data);
 
 void TmModuleReceivePcapFileRegister (void)
 {
-    memset(&pcap_g, 0x00, sizeof(pcap_g));
-
     tmm_modules[TMM_RECEIVEPCAPFILE].name = "ReceivePcapFile";
     tmm_modules[TMM_RECEIVEPCAPFILE].ThreadInit = ReceivePcapFileThreadInit;
     tmm_modules[TMM_RECEIVEPCAPFILE].Func = NULL;