powerpc: Missing tests for NULL after ioremap()

Missing tests after ioremap()
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/platforms/powermac/feature.c

@@ -2589,9 +2589,16 @@ static void __init probe_uninorth(void)
 	if (address == 0)
 		return;
 	uninorth_base = ioremap(address, 0x40000);
+	if (uninorth_base == NULL)
+		return;
 	uninorth_rev = in_be32(UN_REG(UNI_N_VERSION));
-	if (uninorth_maj == 3 || uninorth_maj == 4)
+	if (uninorth_maj == 3 || uninorth_maj == 4) {
 		u3_ht_base = ioremap(address + U3_HT_CONFIG_BASE, 0x1000);
+		if (u3_ht_base == NULL) {
+			iounmap(uninorth_base);
+			return;
+		}
+	}
 
 	printk(KERN_INFO "Found %s memory controller & host bridge"
 	       " @ 0x%08x revision: 0x%02x\n", uninorth_maj == 3 ? "U3" :