nl80211: fix a few memory leaks in reg.c

The first leak occurs when entering the default case
in the switch for the initiator in set_regdom.
The second leaks a platform_device struct if the
platform registration in regulatory_init succeeds but
the sub sequent regulatory hint fails due to no memory.

Signed-off-by: Ola Olsson <ola.olsson@sonymobile.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>