drm/msm/dpu: Avoid calling _dpu_kms_mmu_destroy() on init failure

Fix the error paths in _dpu_kms_mmu_init() to properly
clean up the iommu domain and not call _dpu_kms_mmu_destroy() when
things are only partially setup.
Reviewed-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190617200405.131843-2-sean@poorly.run

drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c

@@ -745,25 +745,20 @@ static int _dpu_kms_mmu_init(struct dpu_kms *dpu_kms)
 	aspace = msm_gem_address_space_create(dpu_kms->dev->dev,
 			domain, "dpu1");
 	if (IS_ERR(aspace)) {
-		ret = PTR_ERR(aspace);
-		goto fail;
+		iommu_domain_free(domain);
+		return PTR_ERR(aspace);
 	}
 
-	dpu_kms->base.aspace = aspace;
-
 	ret = aspace->mmu->funcs->attach(aspace->mmu, iommu_ports,
 			ARRAY_SIZE(iommu_ports));
 	if (ret) {
 		DPU_ERROR("failed to attach iommu %d\n", ret);
 		msm_gem_address_space_put(aspace);
-		goto fail;
+		return ret;
 	}
 
+	dpu_kms->base.aspace = aspace;
 	return 0;
-fail:
-	_dpu_kms_mmu_destroy(dpu_kms);
-
-	return ret;
 }
 
 static struct dss_clk *_dpu_kms_get_clk(struct dpu_kms *dpu_kms,