Revert "ACPI: created a dedicated workqueue for notify() execution"

Revert "ACPI: created a dedicated workqueue for notify() execution"

This reverts commit f5ba46aaef63ce2db16bebbc87497b82acedfffa.

Again.

This same bug has now been introduced twice: it was done earlier by
commit 00d4448b856f3593a34ac3d02b8a62102db9d6bb, only to be reverted
last time in commit 1ece84555a02d520031b4cc307c8e83b9e06068e.

We must NOT try to queue up notify handlers to another thread than the
normal ACPI execution thread, because the notifications on some systems
seem to just keep on accumulating until we run out of memory and/or
threads.

Keeping events within the one deferred execution thread automatically
throttles the events properly.

At least the Compaq N620c will lock up completely on the first thermal
event without this patch reverted.

Cc: David Brownell <david-b@pacbell.net>
Cc: Len Brown <len.brown@intel.com>
Cc: Alexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>