modpost: require a MODULE_DESCRIPTION()

Since commit 1fffe7a34c89 ("script: modpost: emit a warning when the
description is missing"), a module without a MODULE_DESCRIPTION() has
resulted in a warning with make W=1. Since that time, all known
instances of this issue have been fixed. Therefore, now make it an
error if a MODULE_DESCRIPTION() is not present.

Signed-off-by: Jeff Johnson <[e-mail]>
Signed-off-by: Masahiro Yamada <[e-mail]>

scripts/mod/modpost.c

···
 						     namespace);
 		}
 
-		if (extra_warn && !get_modinfo(&info, "description"))
-			warn("missing MODULE_DESCRIPTION() in %s\n", modname);
+		if (!get_modinfo(&info, "description"))
+			error("missing MODULE_DESCRIPTION() in %s\n", modname);
 	}
 
 	for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {