[CVE-2011-2918] perf: Fix software event overflow

[Andy Whitcroft]

CVE-2011-2918
	Under certain circumstances software event overflows go wrong and
	deadlock. Avoid trying to delete a timer from the timer callback.

The fix for this has hit P, oneiric, and lucid via mainline and stable.
Following this email are patches for natty, natty/ti-omap4, maverick,
maverick/ti-omap4, and lucid/fsl-imx51.  They are simple backports from
the stable updates.

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

-apw