- Add encapmtx to protect ip_encap.c global variables (encapsulation
list).
- Unifdef #ifdef 0 pieces of encap_init() which was (and now really
is) basically a no-op.
- Lock encapmtx when walking encaptab, modifying it, comparing
entries, etc.
- Remove spl's.
Note that currently there's no facilite to make sure outstanding
use of encapsulation methods on a table entry have drained bfore
we allow a table entry to be removed. As such, it's currently the
caller's responsibility to make sure that draining takes place.
Reviewed by: mlaier