staging: slicoss: information leak in ETHTOOL_GSET

There are some fields in "edata" which have not been cleared.  One
example is edata.cmd.  It leaks uninitialized stack information to the
user.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>