[PATCH] ebtables: don't compute gap before checking struct type

[PATCH] ebtables: don't compute gap before checking struct type

We cannot compute the gap until we know we have a 'struct ebt_entry'
and not 'struct ebt_entries'.  Failure to check can cause crash.

Tested-by: Santiago Garcia Mantinan <manty@manty.net>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>