Fix an off-by-one error in find_next_zero_string which prevents
allocating the last bit.
[ tglx: arch/x86 adaptation ]
Signed-off-by: Andrew Hastings <abh@cray.com> on behalf of Cray Inc. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>