module: add new state MODULE_STATE_UNFORMED.

You should never look at such a module, so it's excised from all paths
which traverse the modules list.

We add the state at the end, to avoid gratuitous ABI break (ksplice).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 4d5f8d5..8875254 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -1970,6 +1970,8 @@
 
 	kdb_printf("Module                  Size  modstruct     Used by\n");
 	list_for_each_entry(mod, kdb_modules, list) {
+		if (mod->state == MODULE_STATE_UNFORMED)
+			continue;
 
 		kdb_printf("%-20s%8u  0x%p ", mod->name,
 			   mod->core_size, (void *)mod);