[PATCH v2] brcmfmac: check return value of driver_for_each_device()

[Zhang Changzhong <zhangchangzhong@xxxxxxxxxx>]

Fixes the following W=1 kernel build warning(s):

drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c:1576:6: warning:
 variable 'ret' set but not used [-Wunused-but-set-variable]
  1576 |  int ret;
       |      ^~~

driver_for_each_device() has been declared with __must_check, so the
return value should be checked.

Signed-off-by: Zhang Changzhong <zhangchangzhong@xxxxxxxxxx>
---
v2:
- cc linux-wireless
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
index ac54638..6f67fef 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c
@@ -1578,6 +1578,9 @@ void brcmf_usb_exit(void)
 	brcmf_dbg(USB, "Enter\n");
 	ret = driver_for_each_device(drv, NULL, NULL,
 				     brcmf_usb_reset_device);
+	if (ret)
+		brcmf_err("failed to reset all usb devices %d\n", ret);
+
 	usb_deregister(&brcmf_usbdrvr);
 }
 
-- 
2.9.5