PM / hibernate: re-enable nonboot cpus on disable_nonboot_cpus() failure

When disable_nonboot_cpus() fails on some cpu it doesn't bring back all
cpus it managed to offline, a consequent call to enable_nonboot_cpus() is
expected. In hibernation_platform_enter() we don't call
enable_nonboot_cpus() on error so cpus stay offlined.

create_image() and resume_target_kernel() functions handle
disable_nonboot_cpus() faults correctly, hibernation_platform_enter()
is the only one which is doing it wrong.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>