net: forcedeth: Replace context and lock check with a lockdep_assert()

nv_update_stats() triggers a WARN_ON() when invoked from hard interrupt
context because the locks in use are not hard interrupt safe. It also has
an assert_spin_locked() which was the lock check before the lockdep era.

Lockdep has way broader locking correctness checks and covers both issues,
so replace the warning and the lock assert with lockdep_assert_held().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Rain River <rain.1986.08.12@gmail.com>
Cc: Zhu Yanjun <zyjzyj2000@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/nvidia/forcedeth.c

@@ -1666,11 +1666,7 @@ static void nv_update_stats(struct net_device *dev)
 	struct fe_priv *np = netdev_priv(dev);
 	u8 __iomem *base = get_hwbase(dev);
 
-	/* If it happens that this is run in top-half context, then
-	 * replace the spin_lock of hwstats_lock with
-	 * spin_lock_irqsave() in calling functions. */
-	WARN_ONCE(in_irq(), "forcedeth: estats spin_lock(_bh) from top-half");
-	assert_spin_locked(&np->hwstats_lock);
+	lockdep_assert_held(&np->hwstats_lock);
 
 	/* query hardware */
 	np->estats.tx_bytes += readl(base + NvRegTxCnt);