Based on original patch and description from Flavio Leitner <fbl@redhat.com>

When bnx2_reset_task() is called, it will stop,
(re)initialize and start the interface to restore
the working condition.

The bnx2_init_nic() calls bnx2_reset_nic() which will
reset the chip and then calls bnx2_free_skbs() to free
all the skbs.

The problem happens when bnx2_init_chip() fails because
bnx2_reset_nic() will just return skipping the ring
initializations at bnx2_init_all_rings(). Later, the
reset task starts the interface again and the system
crashes due a NULL pointer access (no skb in the ring).

To fix it, we call dev_close() if bnx2_init_nic() fails.
One minor wrinkle to deal with is the cancel_work_sync()
call in bnx2_close() to cancel bnx2_reset_task().  The
call will wait forever because it is trying to cancel
itself and the workqueue will be stuck.

Since bnx2_reset_task() holds the rtnl_lock() and checks
for netif_running() before proceeding, there is no need
to cancel bnx2_reset_task() in bnx2_close() even if
bnx2_close() and bnx2_reset_task() are running concurrently.
The rtnl_lock() serializes the 2 calls.

We need to move the cancel_work_sync() call to
bnx2_remove_one() to make sure it is canceled before freeing
the netdev struct.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Cc: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>