[CVE-2011-1576] core: Fix memory leak/corruption on VLAN GRO_DROP

[Stefan Bader]

introduced by (2.6.30):
	5d0d9be8ef456afc6c3fb5f8aad06ef19b704b05
	gro: Move common completion code into helpers

fixed upstream by (2.6.37):
	3701e51382a026cba10c60b03efabe534fba4ca4
	vlan: Centralize handling of hardware acceleration.

The upstream fix avoids the problem by re-arranging some helper functions.
This minimal fix was picked from the RedHat source package. It matches the
way that the vlan code handled the cases before the merge.

Natty and Oneiric have the upstream fix. Hardy does not even handle GRO.
So only fixes for Lucid and Maverick are required. The two versions for
lucid/fsl-imx51 and the rest only differ by a bit of sourrounding code.