Ethtool: Beautify private flags print

When printing the private flags of the device, align all strings
to have the same length.

Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
[bwh: Fix indentation]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Ethtool: Free memory leak in do_sprivflags()

cmdline is allocated for usage in parse_generic_cmdline(), but is not
released after its final usage.

Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Release version 3.10.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>