It was possible after a dynamic ethernet span was created for a packet to come
in before the dahdi_span was fully initialized. The result would be a NULL
pointer dereference. Now just discard any packets that might come in during
this time window.
Internal-Issue-ID: DAHLIN-280
Reported-by: Pavel Selivanov
Signed-off-by: Shaun Ruffell <sruffell@digium.com>
git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/trunk@10587 a0bf4364-ded3-4de4-8d8a-66a801d63aff