mwifiex: fix a possible double free issue

As drv_info_dump pointer doesn't get reset, we may end up
freeing the allocated memory twice.
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/mwifiex/init.c

@@ -435,6 +435,7 @@ mwifiex_adapter_cleanup(struct mwifiex_adapter *adapter)
 
 	if (adapter->drv_info_dump) {
 		vfree(adapter->drv_info_dump);
+		adapter->drv_info_dump = NULL;
 		adapter->drv_info_size = 0;
 	}
 

drivers/net/wireless/mwifiex/main.c

@@ -886,6 +886,7 @@ void mwifiex_dump_drv_info(struct mwifiex_adapter *adapter)
 
 	if (adapter->drv_info_dump) {
 		vfree(adapter->drv_info_dump);
+		adapter->drv_info_dump = NULL;
 		adapter->drv_info_size = 0;
 	}