hwmon: (coretemp) Fix oops on CPU offlining

hwmon: (coretemp) Fix oops on CPU offlining

This is for stable kernel branch 3.0 only. Previous and later versions
have different code paths and are not affected by this bug.

This is the same fix as "hwmon: (coretemp) Fix oops on driver load"
but for the CPU offlining case. Sorry for missing it at first.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Durgadoss R <durgadoss.r@intel.com>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>