thermal/drivers/cpuidle_cooling: Fix use after error

When the function successfully finishes it logs an information about
the registration of the cooling device and use its name to build the
message. Unfortunately it was freed right before:

drivers/thermal/cpuidle_cooling.c:218 __cpuidle_cooling_register()
	warn: 'name' was already freed.

Fix this by freeing after the message happened.

Fixes: 6fd1b186 ("thermal/drivers/cpuidle_cooling: Use device name instead of auto-numbering")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20210319202522.891061-1-daniel.lezcano@linaro.org