mwifiex: fix use-after-free for FW reinit errors

If we fail to reinit the FW when resetting the device (in the
synchronous version of mwifiex_init_hw_fw() -> mwifiex_fw_dpc()),
mwifiex_fw_dpc() will tear down the interface and free up the adapter.
But we don't actually check for all failure cases of mwifiex_fw_dpc(),
so some of them fall through and dereference adapter->fw_done with a
freed adapter, causing a use-after-free bug.

In any case, mwifiex_fw_dpc() will always signal FW completion -- in the
error OR success case -- so at best, this was repeat work. Let's not do
it.
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/mwifiex/main.c

@@ -1475,7 +1475,6 @@ mwifiex_reinit_sw(struct mwifiex_adapter *adapter)
 	}
 	mwifiex_dbg(adapter, INFO, "%s, successful\n", __func__);
 
-	complete_all(adapter->fw_done);
 	return 0;
 
 err_init_fw: