ARM: bcm: err, don't BUG() on SMC init failures

Several conditions in bcm_kona_smc_init() are handled with BUG_ON().
That function is capable of returning an error, so do that instead.

Also, don't assume of_get_address() returns a valid pointer.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>

arch/arm/mach-bcm/bcm_kona_smc.c

@@ -45,6 +45,7 @@ static const struct of_device_id bcm_kona_smc_ids[] __initconst = {
 int __init bcm_kona_smc_init(void)
 {
 	struct device_node *node;
+	const __be32 *prop_val;
 
 	/* Read buffer addr and size from the device tree node */
 	node = of_find_matching_node(NULL, bcm_kona_smc_ids);
@@ -52,12 +53,17 @@ int __init bcm_kona_smc_init(void)
 		return -ENODEV;
 
 	/* Don't care about size or flags of the DT node */
-	bridge_data.buffer_addr =
-		be32_to_cpu(*of_get_address(node, 0, NULL, NULL));
-	BUG_ON(!bridge_data.buffer_addr);
+	prop_val = of_get_address(node, 0, NULL, NULL);
+	if (!prop_val)
+		return -EINVAL;
+
+	bridge_data.buffer_addr = be32_to_cpu(*prop_val);
+	if (!bridge_data.buffer_addr)
+		return -EINVAL;
 
 	bridge_data.bounce = of_iomap(node, 0);
-	BUG_ON(!bridge_data.bounce);
+	if (!bridge_data.bounce)
+		return -ENOMEM;
 
 	bridge_data.initialized = 1;