ethtool: fix drvinfo strings set in drivers

Use strlcpy where possible to ensure the string is \0 terminated.
Use always sizeof(string) instead of 32, ETHTOOL_BUSINFO_LEN
and custom defines.
Use snprintf instead of sprint.
Remove unnecessary inits of ->fw_version
Remove unnecessary inits of drvinfo struct.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>