net: stmmac: correct priv->eee_sw_timer_en setting

net: stmmac: correct priv->eee_sw_timer_en setting

If we are disabling EEE/LPI, then we should not be enabling software
mode. The only time when we should is if EEE is active, and we are
wanting to use software-timed EEE mode.

Therefore, in the disable path of stmmac_eee_init(), ensure that
priv->eee_sw_timer_en is set false as we are going to be calling
del_timer_sync() on the timer.

This will allow us to simplify some fast-path tests in later patches.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1tXIt7-000MB0-0W@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>