dm: pci: Fix scanning multi-function device

The flag to control whether to scan multi-function device during
enumeration should be cleared at the beginning of each iteration
if the device's function number equals to zero.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index b2909a3..28ea8c5 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -745,6 +745,8 @@
 		struct udevice *dev;
 		ulong class;
 
+		if (!PCI_FUNC(bdf))
+			found_multi = false;
 		if (PCI_FUNC(bdf) && !found_multi)
 			continue;
 		/* Check only the first access, we don't expect problems */