compose: Print out the input hash

We're seeing a case where the change detection apparently isn't
working; let's log the hash we got so it's easier to debug.

Closes: #1393
Approved by: jlebon

src/app/rpmostree-compose-builtin-tree.c

@@ -540,6 +540,8 @@ install_packages_in_root (RpmOstreeTreeComposeContext  *self,
                                                 &ret_new_inputhash, error))
     return FALSE;
 
+  g_print ("Input state hash: %s\n", ret_new_inputhash);
+
   /* Only look for previous checksum if caller has passed *out_unmodified */
   if (self->previous_checksum && out_unmodified != NULL)
     {