drm/amd/display: Fix possible memleak in dp_trigger_hotplug()

If parse_write_buffer_into_params() fails, we should free
wr_buf before return.

Fixes: 6f77b2ac ("drm/amd/display: Add connector HPD trigger debugfs entry")
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c

@@ -1093,8 +1093,10 @@ static ssize_t dp_trigger_hotplug(struct file *f, const char __user *buf,
 	if (parse_write_buffer_into_params(wr_buf, size,
 						(long *)param, buf,
 						max_param_num,
-						&param_nums))
+						&param_nums)) {
+		kfree(wr_buf);
 		return -EINVAL;
+	}
 
 	if (param_nums <= 0) {
 		DRM_DEBUG_DRIVER("user data not be read\n");