[PATCH] drm/bridge: anx7625: check the return on anx7625_aux_trans

[trix at redhat.com]

From: Tom Rix <trix at redhat.com>

Clang static analysis reports this issue
anx7625.c:876:13: warning: The left operand of '&' is
  a garbage value
  if (!(bcap & 0xOA01)) {
        ~~~~ ^

bcap is only set by a successful call to
anx7625_aux_trans().  So check.

Fixes: cd1637c7e480 ("drm/bridge: anx7625: add HDCP support")
Signed-off-by: Tom Rix <trix at redhat.com>
---
 drivers/gpu/drm/bridge/analogix/anx7625.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 633618bafd75d..f02ac079ed2ec 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -872,7 +872,10 @@ static int anx7625_hdcp_enable(struct anx7625_data *ctx)
 	}
 
 	/* Read downstream capability */
-	anx7625_aux_trans(ctx, DP_AUX_NATIVE_READ, 0x68028, 1, &bcap);
+	ret = anx7625_aux_trans(ctx, DP_AUX_NATIVE_READ, 0x68028, 1, &bcap);
+	if (ret < 0)
+		return ret;
+
 	if (!(bcap & 0x01)) {
 		pr_warn("downstream not support HDCP 1.4, cap(%x).\n", bcap);
 		return 0;
-- 
2.26.3