drivers/net: use tasklet_kill in device remove/close process

drivers/net: use tasklet_kill in device remove/close process

Some driver uses tasklet_disable in device remove/close process,
tasklet_disable will inc tasklet->count and return. If the tasklet
is not handled yet because some softirq pressure, the tasklet will
placed on the tasklet_vec, never have a chance to excute. This might
lead to ksoftirqd heavy loaded, wakeup with pending_softirq, but
tasklet is disabled. tasklet_kill should be used in this case.

Signed-off-by: Xiaotian Feng <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: [email protected]
Signed-off-by: David S. Miller <[email protected]>