iwlwifi: mvm: fix %16 to %016 print format

With just %16, it means 16 characters padding, but we really
don't want to print "0x         1F4547B", but instead want to
have this filled with zeroes, so we need the 0.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>