net: phy: Correctly process PHY_HALTED in phy_stop_machine()

Marc reported that he was not getting the PHY library adjust_link()
callback function to run when calling phy_stop() + phy_disconnect()
which does not indeed happen because we set the state machine to
PHY_HALTED but we don't get to run it to process this state past that
point.

Fix this with a synchronous call to phy_state_machine() in order to have
the state machine actually act on PHY_HALTED, set the PHY device's link
down, turn the network device's carrier off and finally call the
adjust_link() function.
Reported-by: NMarc Gonzalez <marc_gonzalez@sigmadesigns.com>
Fixes: a390d1f3 ("phylib: convert state_queue work to delayed_work")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NMarc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/phy/phy.c

@@ -749,6 +749,9 @@ void phy_stop_machine(struct phy_device *phydev)
 	if (phydev->state > PHY_UP && phydev->state != PHY_HALTED)
 		phydev->state = PHY_UP;
 	mutex_unlock(&phydev->lock);
+
+	/* Now we can run the state machine synchronously */
+	phy_state_machine(&phydev->state_queue.work);
 }
 
 /**