kbuild: genksyms: Include extern information in dumps

The extern flag currently is not included in type dump files
(genksyms --dump-types). Include that flag there for completeness.
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/genksyms/genksyms.c

@@ -545,6 +545,8 @@ int main(int argc, char **argv)
 			}
 			fputs(sym->name, dumpfile);
 			putc(' ', dumpfile);
+			if (sym->is_extern)
+				fputs("extern ", dumpfile);
 			print_list(dumpfile, sym->defn);
 			putc('\n', dumpfile);