This bug seems to be due to commit 27ae60f8 ("ipw2x00: replace
"ieee80211" with "libipw" where appropriate"), where Pavel did this:

-       libipw_proc = proc_mkdir(DRV_NAME, init_net.proc_net);
+       libipw_proc = proc_mkdir("ieee80211", init_net.proc_net);

but then the cleanup was kept as

        remove_proc_entry(DRV_NAME, init_net.proc_net);

in both places (both in the failure case and in the unload case). The
error string is also total crap, and says

     "Unable to create " DRV_NAME " proc directory\n");

Even though it doesn't actually create a proc directory named DRV_NAME at all.

So that patch looks like total and utter crap to me. The commit message says

  "Keep /proc/net/ieee80211 under the original name to avoid breaking user
    interface."

but the thing is, it really didn't fix anything but that one create
thing. It needs to fix all the other cases too.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>