PCI: tegra: Fix return value check of pm_runtime_get_sync()

pm_runtime_get_sync() returns the device's usage counter. This might
be >0 if the device is already powered up or CONFIG_PM is disabled.

Abort probe function on real error only.

Fixes: da76ba5 ("PCI: tegra: Add power management support")
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: David Engraf <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Signed-off-by: Lorenzo Pieralisi <[email protected]>
Acked-by: Andrew Murray <[email protected]>
Cc: [email protected]	# v4.17+

Author: dengraf

drivers/pci/controller/pci-tegra.c

@@ -2798,7 +2798,7 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 
 	pm_runtime_enable(pcie->dev);
 	err = pm_runtime_get_sync(pcie->dev);
-	if (err) {
+	if (err < 0) {
 		dev_err(dev, "fail to enable pcie controller: %d\n", err);
 		goto teardown_msi;
 	}