net: dp83640: fix improper double spin locking.

net: dp83640: fix improper double spin locking.

[ Upstream commit adbe088f6f8b0b7701fe07f51fe6f2bd602a6665 ]

A pair of nested spin locks was introduced in commit 63502b8d0
"dp83640: Fix receive timestamp race condition".

Unfortunately the 'flags' parameter was reused for the inner lock,
clobbering the originally saved IRQ state.  This patch fixes the issue
by changing the inner lock to plain spin_lock without irqsave.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>