crypto: api - Move module sig ifdef into accessor function

Currently we're hiding mod->sig_ok under an ifdef in open code.
This patch adds a module_sig_ok accessor function and removes that
ifdef.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/include/linux/module.h b/include/linux/module.h
index c883b86..1e54360 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -655,4 +655,16 @@
 static inline void module_bug_cleanup(struct module *mod) {}
 #endif	/* CONFIG_GENERIC_BUG */
 
+#ifdef CONFIG_MODULE_SIG
+static inline bool module_sig_ok(struct module *module)
+{
+	return module->sig_ok;
+}
+#else	/* !CONFIG_MODULE_SIG */
+static inline bool module_sig_ok(struct module *module)
+{
+	return true;
+}
+#endif	/* CONFIG_MODULE_SIG */
+
 #endif /* _LINUX_MODULE_H */