Fix for Coverity
Remove unused variable
fr_socket() returns a negative number for error
Added VERIFY_RP for RADIUS_PACKET
Checks for case which shouldn't happen
Remove dead code
Initialize variable
Dereference after NULL check

Won't be an issue, but the code was wrong
Add missing unlock

for when malloc fails.
Return if alloc fails
Can't get a VP from a VPT if no VP exists
Check length of ethernet VP