x86: queensbay: Return directly if IGD / SDVO were already disabled

Initialize 'igd' and 'sdvo' to NULL so that we just need to test
them against NULL later, to be compatible with that case that IGD
and SDVO devices were already in disabled state.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/cpu/queensbay/tnc.c b/arch/x86/cpu/queensbay/tnc.c
index 782ed86..4a00862 100644
--- a/arch/x86/cpu/queensbay/tnc.c
+++ b/arch/x86/cpu/queensbay/tnc.c
@@ -18,19 +18,17 @@
 
 static int __maybe_unused disable_igd(void)
 {
-	struct udevice *igd, *sdvo;
+	struct udevice *igd = NULL;
+	struct udevice *sdvo = NULL;
 	int ret;
 
-	ret = dm_pci_bus_find_bdf(TNC_IGD, &igd);
-	if (ret)
-		return ret;
-	if (!igd)
-		return 0;
-
-	ret = dm_pci_bus_find_bdf(TNC_SDVO, &sdvo);
-	if (ret)
-		return ret;
-	if (!sdvo)
+	/*
+	 * In case the IGD and SDVO devices were already in disabled state,
+	 * we should return and not proceed any further.
+	 */
+	dm_pci_bus_find_bdf(TNC_IGD, &igd);
+	dm_pci_bus_find_bdf(TNC_SDVO, &sdvo);
+	if (!igd || !sdvo)
 		return 0;
 
 	/*