mwifiex: handle association failure case correctly

Currently even if association is failed "iw link" shows some
information about connected BSS and "Tx timeout" error is seen in
dmesg log.

This patch fixes below issues in the code to handle assoc failure
case correctly.
1) "status" variable in mwifiex_wait_queue_complete() is not
correctly updated. Hence driver doesn't inform cfg80211 stack
about association failure.
2) During association network queues are stopped but carrier is
not cleared, which gives Tx timeout error in failure case

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>