Per suggestion from Vladimir, eliminate check_wildcard_match(), which

Per suggestion from Vladimir, eliminate check_wildcard_match(), which
was only being used by insmod these days.

Also, I spent a minute adjusting insmod so that it first searches
/lib/modules/`uname -r` and then (if that fails) searches /lib/modules,
which makes bb insmod behave much more like the real insmod, and should
avoid nasty surprises (such as the recent "Modutils vs. Busybox..."
thread).
 -Erik