Added WARN_MSG function to deal with missing ethtool
Loop if the user puts a string instead of a number
Merge pull request #323 from LocutusOfBorg/fix-gets

Loop if the user puts a string instead of a number
Merge pull request #324 from eaescob/warn-msg

Added WARN_MSG function to deal with missing ethtool
Fixed warning printf if no ethtool is found
Merge pull request #325 from LocutusOfBorg/fix-warning-printf

Fixed warning printf