[CVE-2011-1162] scrub tpm data before free

[Andy Whitcroft]

CVE-2011-1162
	char/tpm: zero buffer after copying to userspace

The fix for this issue has hit lucid, oneiric and precise via mainline
and stable.  Following this email are three patches, one for hardy, one
for lucid/fsl-imx51, maverick and maverick/ti-omap4, and one for natty
and natty/ti-omap4.  The hardy patch is a very minor backport, the other
two are simple cherry-picks only differing in context.

Proposing for hardy, lucid/fsl-imx51, maverick, maverick/ti-omap4, natty
and natty/ti-omap4.

-apw