disp: msm: Address static analysis issues

Avoid various possible nullptr dereferences.
Addresses various issues highlighted by static analysis.

Change-Id: I36d34d610b37bf2799a7e34cd1de8b909b5c0ae4
Signed-off-by: Nisarg Bhavsar <quic_bhavsar@quicinc.com>

msm/dp/dp_lphw_hpd.c

@@ -345,7 +345,7 @@ struct dp_hpd *dp_lphw_hpd_get(struct device *dev, struct dp_parser *parser,
 {
 	int rc = 0;
 	const char *hpd_gpio_name = "qcom,dp-hpd-gpio";
-	struct dp_lphw_hpd_private *lphw_hpd;
+	struct dp_lphw_hpd_private *lphw_hpd = NULL;
 	unsigned int gpio;
 
 	if (!dev || !parser || !cb) {
@@ -358,7 +358,7 @@ struct dp_hpd *dp_lphw_hpd_get(struct device *dev, struct dp_parser *parser,
 	if (!gpio_is_valid(gpio)) {
 		DP_DEBUG("%s gpio not specified\n", hpd_gpio_name);
 		rc = -EINVAL;
-		goto gpio_error;
+		goto error;
 	}
 
 	lphw_hpd = devm_kzalloc(dev, sizeof(*lphw_hpd), GFP_KERNEL);