iwmc3200top: clean up fw_download

1. removed redundant NULL-pointers checks in iwmct_fw_load
as release_firmware and kfree are NULL pointer friendly
2. remove redundant memset of the parser since the structure
is fully initialized in iwmct_fw_parser_init function

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>