cfg80211: avoid flushing the global workqueue for core reg hints

When cfg80211 starts it will send a core regulatory hint. This is
sent to the global workqueue but we force processing of it by
flushing the global workqueue. The flushing was done since
cfg80211 needs last_request to always be populated.

Avoid flushing the global workqueue by processing the work
required immediately instead of putting it into a linked
list and processing it after the flush.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>