of/platform: Fix fn definitons for of_link_is_valid() and of_link_property()

of_link_is_valid() can be static since it's not used anywhere else.

of_link_property() return type should have been int instead of bool.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20190806192654.138605-1-saravanak@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/of/platform.c

@@ -506,7 +506,7 @@ int of_platform_default_populate(struct device_node *root,
 }
 EXPORT_SYMBOL_GPL(of_platform_default_populate);
 
-bool of_link_is_valid(struct device_node *con, struct device_node *sup)
+static bool of_link_is_valid(struct device_node *con, struct device_node *sup)
 {
 	of_node_get(sup);
 	/*
@@ -625,7 +625,7 @@ static const struct supplier_bindings bindings[] = {
 	{ },
 };
 
-static bool of_link_property(struct device *dev, struct device_node *con_np,
+static int of_link_property(struct device *dev, struct device_node *con_np,
 			     const char *prop)
 {
 	struct device_node *phandle;