drm/amdgpu: fix ref count leak in amdgpu_display_crtc_set_config

in amdgpu_display_crtc_set_config, the call to pm_runtime_get_sync
increments the counter even in case of failure, leading to incorrect
ref count. In case of failure, decrement the ref count before returning.

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_display.c

@@ -282,7 +282,7 @@ int amdgpu_display_crtc_set_config(struct drm_mode_set *set,
 
 	ret = pm_runtime_get_sync(dev->dev);
 	if (ret < 0)
-		return ret;
+		goto out;
 
 	ret = drm_crtc_helper_set_config(set, ctx);
 
@@ -297,7 +297,7 @@ int amdgpu_display_crtc_set_config(struct drm_mode_set *set,
 	   take the current one */
 	if (active && !adev->have_disp_power_ref) {
 		adev->have_disp_power_ref = true;
-		return ret;
+		goto out;
 	}
 	/* if we have no active crtcs, then drop the power ref
 	   we got before */
@@ -306,6 +306,7 @@ int amdgpu_display_crtc_set_config(struct drm_mode_set *set,
 		adev->have_disp_power_ref = false;
 	}
 
+out:
 	/* drop the power reference we got coming in here */
 	pm_runtime_put_autosuspend(dev->dev);
 	return ret;