[PATCH] staging: wilc1000: fix double mutex_unlock on failure path in wilc_wlan_cleanup()

[Alexey Khoroshilov <khoroshilov@ispras.ru>]

If hif_read_reg() or hif_write_reg() fail in wilc_wlan_cleanup(),
it calls release_bus() and continues execution. But it leads to double
release_bus() call that means double unlock of g_linux_wlan->hif_cs mutex.

The patch adds return in case of failure.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
---
 drivers/staging/wilc1000/wilc_wlan.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/staging/wilc1000/wilc_wlan.c b/drivers/staging/wilc1000/wilc_wlan.c
index c02665747705..cd7f52a51173 100644
--- a/drivers/staging/wilc1000/wilc_wlan.c
+++ b/drivers/staging/wilc1000/wilc_wlan.c
@@ -1703,12 +1703,14 @@ void wilc_wlan_cleanup(struct net_device *dev)
 	if (!ret) {
 		PRINT_ER("Error while reading reg\n");
 		release_bus(RELEASE_ALLOW_SLEEP);
+		return;
 	}
 	PRINT_ER("Writing ABORT reg\n");
 	ret = p->hif_func.hif_write_reg(WILC_GP_REG_0, (reg | ABORT_INT));
 	if (!ret) {
 		PRINT_ER("Error while writing reg\n");
 		release_bus(RELEASE_ALLOW_SLEEP);
+		return;
 	}
 	release_bus(RELEASE_ALLOW_SLEEP);
 	/**
-- 
1.9.1