Sanity check to catch a rare segv
Fix up i386 socketcall segfault.

This was an ugly bug.
Occasionally the watchdog would segv after trying to print info
about syscall number -1.  It happened because socketcall was trying
to lookup "socket", which doesn't exist on i386.

Instead, we repurpose the sanitise function from socket into a
function that generates family/type/protocol triplets.