iwlwifi: mvm: add description to second BAD_COMMAND assert number

Depending on exactly what happens in the FW, an invalid host-command
could result in either assert 0x38 or 0x39. Add 0x39 to the assert-name
table.

Signed-off-by: Naftali Goldstein <naftali.goldstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>