crypto/conf: gcc build warning fix

Fix the gcc build warning from conf_sap.c:
variable flags set but not used [-Wunused-but-set-variable]
variable appname set but not used [-Wunused-but-set-variable]
variable filename set but not used [-Wunused-but-set-variable]

CLA: trivial

Signed-off-by: Gang Chen <gang.c.chen@intel.com>

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from #20347)

crypto/conf/conf_sap.c

@@ -43,16 +43,19 @@ void OPENSSL_config(const char *appname)
 int openssl_config_int(const OPENSSL_INIT_SETTINGS *settings)
 {
     int ret = 0;
+#if defined(OPENSSL_INIT_DEBUG) || !defined(OPENSSL_SYS_UEFI)
     const char *filename;
     const char *appname;
     unsigned long flags;
+#endif
 
     if (openssl_configured)
         return 1;
-
+#if defined(OPENSSL_INIT_DEBUG) || !defined(OPENSSL_SYS_UEFI)
     filename = settings ? settings->filename : NULL;
     appname = settings ? settings->appname : NULL;
     flags = settings ? settings->flags : DEFAULT_CONF_MFLAGS;
+#endif
 
 #ifdef OPENSSL_INIT_DEBUG
     fprintf(stderr, "OPENSSL_INIT: openssl_config_int(%s, %s, %lu)\n",