igmp: Fix optimized code for igmp_remove_group

The code in the for loop checks tmp_group->next == group, so current code
actually checks from the 3rd entry in the linked groups list. Fix it.

Fixes: 5c1dd6a4c65b ("Optimization in igmp_remove_group() pointed out by Axel Lin")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
1 file changed