Revert "x86: Cleanup highmap after brk is concluded"

Revert "x86: Cleanup highmap after brk is concluded"

BugLink: http://bugs.launchpad.net/bugs/761134

This reverts upstream commit e5f15b45ddf3afa2bbbb10c7ea34fb32b6de0a0e

It caused problems in the stable tree and should not have been there.

Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>