Description of problem:
tcpdump sets only effective uid and gid when -Z option is used (enabled by
default) with -C option. It is a result of the patch for bug #176010.

Setting only euid removes an extra security layer that might otherwise have
mitigated an eventual security problem.

A better solution for the bug is to call setuid() before the first file is
opened, then all files will have pcap owner and tcpdump can drop root privileges
completely.

Version-Release number of selected component (if applicable):
tcpdump-3.9.5-3.fc7

Steps to Reproduce:
1. tcpdump -C 1 -w dump
2. cat /proc/{tcpdump}/status | grep Uid
  
Actual results:
Uid:	0	77	0	77

Expected results:
Uid:	77	77	77	77