init: add comments to keep initcall-names in sync with initcall levels

main.c has initcall_level_names[] for parse_args to print in debug messages,
add comments to keep them in sync with initcalls defined in init.h.

Also add "loadable" into comment re not using *_initcall macros in
modules, to disambiguate from kernel/params.c and other builtins.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

include/linux/init.h

@@ -191,6 +191,7 @@ extern bool initcall_debug;
  * initializes variables that couldn't be statically initialized.
  *
  * This only exists for built-in code, not for modules.
+ * Keep main.c:initcall_level_names[] in sync.
  */
 #define pure_initcall(fn)		__define_initcall("0",fn,0)
 
@@ -280,7 +281,7 @@ void __init parse_early_options(char *cmdline);
 
 #else /* MODULE */
 
-/* Don't use these in modules, but some people do... */
+/* Don't use these in loadable modules, but some people do... */
 #define early_initcall(fn)		module_init(fn)
 #define core_initcall(fn)		module_init(fn)
 #define postcore_initcall(fn)		module_init(fn)

init/main.c

@@ -724,6 +724,7 @@ static initcall_t *initcall_levels[] __initdata = {
 	__initcall_end,
 };
 
+/* Keep these in sync with initcalls in include/linux/init.h */
 static char *initcall_level_names[] __initdata = {
 	"early",
 	"core",