iwlwifi: tt: move ucode_loaded check under mutex

iwlwifi: tt: move ucode_loaded check under mutex

[ Upstream commit d9954405758a0cbbe258d9b4d4dc12a06fa48a28 ]

The ucode_loaded check should be under the mutex, since it can
otherwise change state after we looked at it and before we got
the mutex. Fix that.

Fixes: 5c89e7bc557e ("iwlwifi: mvm: add registration to cooling device")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>