drm/msm/phy/dsi_phy: silence -EPROBE_DEFER warnings

The following errors show up when booting the Nexus 5:

msm_dsi_phy fd922a00.dsi-phy: [drm:dsi_phy_driver_probe] *ERROR*
 dsi_phy_regulator_init: failed to init regulator, ret=-517
msm_dsi_phy fd922a00.dsi-phy: [drm:dsi_phy_driver_probe] *ERROR*
 dsi_phy_driver_probe: failed to init regulator

dsi_phy_regulator_init() already logs the error, so no need to log
the same error a second time in dsi_phy_driver_probe(). This patch
also changes dsi_phy_regulator_init() to not log the error if the
error code is -EPROBE_DEFER to reduce noise in dmesg.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
[add some {}'s]
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/dsi/phy/dsi_phy.c

@@ -396,8 +396,12 @@ static int dsi_phy_regulator_init(struct msm_dsi_phy *phy)
 
 	ret = devm_regulator_bulk_get(dev, num, s);
 	if (ret < 0) {
-		DRM_DEV_ERROR(dev, "%s: failed to init regulator, ret=%d\n",
+		if (ret != -EPROBE_DEFER) {
+			DRM_DEV_ERROR(dev,
+				      "%s: failed to init regulator, ret=%d\n",
 				      __func__, ret);
+		}
+
 		return ret;
 	}
 
@@ -584,10 +588,8 @@ static int dsi_phy_driver_probe(struct platform_device *pdev)
 	}
 
 	ret = dsi_phy_regulator_init(phy);
-	if (ret) {
-		DRM_DEV_ERROR(dev, "%s: failed to init regulator\n", __func__);
+	if (ret)
 		goto fail;
-	}
 
 	phy->ahb_clk = msm_clk_get(pdev, "iface");
 	if (IS_ERR(phy->ahb_clk)) {