mac80211_hwsim: Make sure NEW_RADIO contains final name

ieee80211_alloc_hw_nm will validate the requested name (if any) before
creating the new device and may use a name different from the one
requested rather than fail.  Make sure the HWSIM_CMD_NEW_RADIO
event/response generated has the final name or userspace will receive
the wrong name.  Note that mac80211_hwsim_new_radio may now modify
params.

A check for duplicate radio name could be added separately.

Signed-off-by: Andrew Zaborowski <andrew.zaborowski@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>