kbuild: soften MODULE_LICENSE check

Only modules that has other MODULE_* content
shall have the MODULE_LICENSE() tag.

This fixes allmodconfig build on my box.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/mod/modpost.c

@@ -1552,8 +1552,8 @@ static void read_symbols(char *modname)
 	}
 
 	license = get_modinfo(info.modinfo, info.modinfo_len, "license");
-	if (!license && !is_vmlinux(modname))
-		fatal("modpost: missing MODULE_LICENSE() in %s\n"
+	if (info.modinfo && !license && !is_vmlinux(modname))
+		warn("modpost: missing MODULE_LICENSE() in %s\n"
 		     "see include/linux/module.h for "
 		     "more information\n", modname);
 	while (license) {