MODSIGN: Specify the hash algorithm on sign-file command line

Make the script usable without a .config file.

Signed-off-by: Michal Marek <mmarek@suse.cz>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/Makefile b/Makefile
index 253a455..77ea707 100644
--- a/Makefile
+++ b/Makefile
@@ -723,7 +723,7 @@
 MODSECKEY = ./signing_key.priv
 MODPUBKEY = ./signing_key.x509
 export MODPUBKEY
-mod_sign_cmd = perl $(srctree)/scripts/sign-file $(MODSECKEY) $(MODPUBKEY)
+mod_sign_cmd = perl $(srctree)/scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODSECKEY) $(MODPUBKEY)
 else
 mod_sign_cmd = true
 endif