rtlwifi: rtl8192c: Add init codes for "fw_version" and "fw_subversion".

The variable "fw_version" is used in the _ResetDigitalProcedure1().
but It is not initialized. so I add init codes for "fw_version" and
"fw_subversion".

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>