(trivial) Fix compiler warning in kernel/modules.c

Building with CONFIG_KALLSYMS=n gives following warning:

/mnt/src/linux-git/kernel/module.c: In function ‘post_relocation’:
/mnt/src/linux-git/kernel/module.c:2534:2: warning: passing argument 2 of ‘add_kallsyms’ discards qualifiers from pointer target type
/mnt/src/linux-git/kernel/module.c:2038:13: note: expected ‘struct load_info *’ but argument is of type ‘const struct load_info *’
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

kernel/module.c

@@ -2037,7 +2037,7 @@ static inline void layout_symtab(struct module *mod, struct load_info *info)
 {
 }
 
-static void add_kallsyms(struct module *mod, struct load_info *info)
+static void add_kallsyms(struct module *mod, const struct load_info *info)
 {
 }
 #endif /* CONFIG_KALLSYMS */