net: stmmac: fix .ndo_fix_features()

net: stmmac: fix .ndo_fix_features()

netdev features documentation requires that .ndo_fix_features() is
stateless: it shouldn't modify driver state. Yet, stmmac_fix_features()
does exactly that, changing whether GSO frames are processed by the
driver.

Move this code to stmmac_set_features() instead, which is the correct
place for it. We don't need to check whether TSO is supported; this
is already handled via the setup of netdev->hw_features, and we are
guaranteed that if netdev->hw_features indicates that a feature is
not supported, .ndo_set_features() won't be called with it set.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1w7pt9-0000000East-1YAO@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>