rtlwifi: fix for race condition when firmware is cached

rtlwifi: fix for race condition when firmware is cached

commit 574e02abaf816b582685805f0c1150ca9f1f18ee upstream.

In commit b0302ab, the rtlwifi family of drivers was converted to use
asynchronous firmware loading. Unfortumately, the implementation was
racy, and the ieee80211 routines could be started before rtl_init_core()
was called to setup the data.

This patch fixes the bug noted in https://bugzilla.kernel.org/show_bug.cgi?id=43187.

Reported-by: Joshua Roys <Joshua.Roys@gtri.gatech.edu>
Tested-by: Neptune Ning <frostyplanet@gmail.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>