hwmon: coretemp: enable coretemp device add operation failure

If one coretemp device can't be added, it should allow subsequent adding
operation because every new-added device will create a new sysfs group,
not an additional sensor sys entry.

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Cc: Rudolf Marek <r.marek@assembler.cz>
Cc: Huaxu Wan <huaxu.wan@intel.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>