mod: removed unused safchain/ethtool version

Signed-off-by: W. Andrew Denton <[email protected]>

Author: W. Andrew Denton

go.sum

@@ -241,8 +241,6 @@ github.com/prometheus/procfs v0.6.0/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1
 github.com/prometheus/procfs v0.7.2 h1:zE6zJjRS9S916ptrZ326OU0++1XRwHgxkvCFflxx6Fo=
 github.com/prometheus/procfs v0.7.2/go.mod h1:cz+aTbrPOrUb4q7XlbU9ygM+/jj0fzG6c1xBZuNvfVA=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
-github.com/safchain/ethtool v0.0.0-20201023143004-874930cb3ce0 h1:eskphjc5kRCykOJyX7HHVbJCs25/8knprttvrVvEd8o=
-github.com/safchain/ethtool v0.0.0-20201023143004-874930cb3ce0/go.mod h1:Z0q5wiBQGYcxhMZ6gUqHn6pYNLypFAvaL3UvgZLR0U4=
 github.com/safchain/ethtool v0.0.0-20210803160452-9aa261dae9b1 h1:ZFfeKAhIQiiOrQaI3/znw0gOmYpO28Tcu1YaqMa/jtQ=
 github.com/safchain/ethtool v0.0.0-20210803160452-9aa261dae9b1/go.mod h1:Z0q5wiBQGYcxhMZ6gUqHn6pYNLypFAvaL3UvgZLR0U4=
 github.com/siebenmann/go-kstat v0.0.0-20210513183136-173c9b0a9973 h1:GfSdC6wKfTGcgCS7BtzF5694Amne1pGCSTY252WhlEY=