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>
diff --git a/net/wireless/ethtool.c b/net/wireless/ethtool.c
index 48c48ff..e37862f 100644
--- a/net/wireless/ethtool.c
+++ b/net/wireless/ethtool.c
@@ -15,10 +15,10 @@
 	strlcpy(info->version, init_utsname()->release, sizeof(info->version));
 
 	if (wdev->wiphy->fw_version[0])
-		strncpy(info->fw_version, wdev->wiphy->fw_version,
+		strlcpy(info->fw_version, wdev->wiphy->fw_version,
 			sizeof(info->fw_version));
 	else
-		strncpy(info->fw_version, "N/A", sizeof(info->fw_version));
+		strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 
 	strlcpy(info->bus_info, dev_name(wiphy_dev(wdev->wiphy)),
 		sizeof(info->bus_info));