net: tools: Modify pcap functions on 15.4 monitor tool

Now monitor tool uses host pcap/pcap.h header file for
related structs. Removed unused functions. Modified
pcap_creation and pcap_write functions.

Change-Id: I918bef483e81cf3001841a9b86a100388025b28c
Signed-off-by: Ravi kumar Veeramally <ravikumar.veeramally@linux.intel.com>