modpost: move struct namespace_list to modpost.c

There is no good reason to define struct namespace_list in modpost.h

struct module has pointers to struct namespace_list, but that does
not require the definition of struct namespace_list.

Move it to modpost.c.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

scripts/mod/modpost.c

@@ -270,6 +270,11 @@ static struct symbol *find_symbol(const char *name)
 	return NULL;
 }
 
+struct namespace_list {
+	struct namespace_list *next;
+	char namespace[];
+};
+
 static bool contains_namespace(struct namespace_list *list,
 			       const char *namespace)
 {

scripts/mod/modpost.h

@@ -109,11 +109,6 @@ buf_printf(struct buffer *buf, const char *fmt, ...);
 void
 buf_write(struct buffer *buf, const char *s, int len);
 
-struct namespace_list {
-	struct namespace_list *next;
-	char namespace[];
-};
-
 struct module {
 	struct module *next;
 	int gpl_compatible;