drm/brige/megachips: Add checking if ge_b850v3_lvds_init() is working correctly

If ge_b850v3_lvds_init() does not allocate memory for ge_b850v3_lvds_ptr,
then a null pointer dereference is accessed.

The patch adds checking of the return value of ge_b850v3_lvds_init().

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

Signed-off-by: Nadezda Lutovinova <[e-mail]>
Signed-off-by: Sam Ravnborg <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c

···
 				       const struct i2c_device_id *id)
 {
 	struct device *dev = &stdp4028_i2c->dev;
+	int ret;
 
-	ge_b850v3_lvds_init(dev);
+	ret = ge_b850v3_lvds_init(dev);
+
+	if (ret)
+		return ret;
 
 	ge_b850v3_lvds_ptr->stdp4028_i2c = stdp4028_i2c;
 	i2c_set_clientdata(stdp4028_i2c, ge_b850v3_lvds_ptr);
···
 				       const struct i2c_device_id *id)
 {
 	struct device *dev = &stdp2690_i2c->dev;
+	int ret;
 
-	ge_b850v3_lvds_init(dev);
+	ret = ge_b850v3_lvds_init(dev);
+
+	if (ret)
+		return ret;
 
 	ge_b850v3_lvds_ptr->stdp2690_i2c = stdp2690_i2c;
 	i2c_set_clientdata(stdp2690_i2c, ge_b850v3_lvds_ptr);