wlan: scan engine response timeout.

When INIT SCAN request as part of remain on channel is issued
and imediately afterward cancel ROC is issued, driver wait till
the ready on channel timeout happens, if driver doesn't get any
ready indication within timeout , it is not able to cancel ROC
and system gets stuck leading to crash. As a part of fix, added
a flag which would indicate that a pending cancel ROC is present
so that  new cancel ROC is issued  directly from driver.

Change-Id: I74d64d10148ffc4e6c013f354e353cf4a1eea139
CRs-Fixed: 658069
diff --git a/CORE/HDD/inc/wlan_hdd_main.h b/CORE/HDD/inc/wlan_hdd_main.h
index 18d7dee..5be4fcd 100644
--- a/CORE/HDD/inc/wlan_hdd_main.h
+++ b/CORE/HDD/inc/wlan_hdd_main.h
@@ -585,6 +585,7 @@
   vos_timer_t hdd_remain_on_chan_timer;
   action_pkt_buffer_t action_pkt_buff;
   v_U32_t hdd_remain_on_chan_cancel_in_progress;
+  tANI_BOOLEAN is_pending_roc_cancelled;
 }hdd_remain_on_chan_ctx_t;
 
 typedef enum{