Add additional error handling to pcidev_readbar() callers

This is mostly a leftover of Niklas' "remove exit call from pcidev_init" patch.
While not explicitly necessary detecting errors early is usually a good idea.

Corresponding to flashrom svn r1718.

Signed-off-by: Niklas Söderlund <niso@kth.se>
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
diff --git a/satasii.c b/satasii.c
index 37266eb..83dc62c 100644
--- a/satasii.c
+++ b/satasii.c
@@ -85,9 +85,13 @@
 
 	if ((id == 0x3132) || (id == 0x3124)) {
 		addr = pcidev_readbar(dev, PCI_BASE_ADDRESS_0);
+		if (!addr)
+			return 1;
 		reg_offset = 0x70;
 	} else {
 		addr = pcidev_readbar(dev, PCI_BASE_ADDRESS_5);
+		if (!addr)
+			return 1;
 		reg_offset = 0x50;
 	}