Fixes neighbor solicit issue in ubuntu/Centos

In linux_pull_outer_headers(), ICMP header size was counted twice before skb_pull. this resulted in skb_pull
failing for the neighbor solicit packets. This bug fixes the same.

Change-Id: I878d6ae0d63ac5e7446a82aa462718f0589cb367
Closes-Bug: 1392638
Merge "Fixes neighbor solicit issue in ubuntu/Centos"