crypto: api - Fix build error when modules are disabled

The commit 59afdc7b ("crypto:
api - Move module sig ifdef into accessor function") broke the
build when modules are completely disabled because we directly
dereference module->name.

This patch fixes this by using the accessor function module_name.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

crypto/algapi.c

@@ -46,7 +46,7 @@ static inline void crypto_check_module_sig(struct module *mod)
 {
 	if (fips_enabled && mod && !module_sig_ok(mod))
 		panic("Module %s signature verification failed in FIPS mode\n",
-		      mod->name);
+		      module_name(mod));
 }
 
 static int crypto_check_alg(struct crypto_alg *alg)