of: correct of_console_check()'s return value

The comments above of_console_check() say that it will return TRUE if it
registers a preferred console, but add_preferred_console() uses a
0-equals-success convention, so this leaves of_console_check() with an
inconsistent policy for its return values.

Fortunately, nobody was actually checking the return value of
of_console_check(), so this isn't significant at the moment.

But let's match the comments, so we're doing what we say.

Fixes: 3482f2c5 ('of: Create of_console_check() for selecting a console specified in /chosen')
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

drivers/of/base.c

@@ -1986,7 +1986,7 @@ bool of_console_check(struct device_node *dn, char *name, int index)
 {
 	if (!dn || dn != of_stdout || console_set_on_cmdline)
 		return false;
-	return add_preferred_console(name, index, NULL);
+	return !add_preferred_console(name, index, NULL);
 }
 EXPORT_SYMBOL_GPL(of_console_check);