Elide OPENSSL_INIT_set_config_filename() for no-stdio build

Strictly speaking, it isn't stdio and file access which offend me here;
it's the fact that UEFI doesn't provide a strdup() function. But the
fact that it's pointless without file access is a good enough excuse for
compiling it out.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>

crypto/conf/conf_lib.c

@@ -387,12 +387,14 @@ OPENSSL_INIT_SETTINGS *OPENSSL_INIT_new(void)
 }
 
 
+#ifndef OPENSSL_NO_STDIO
 void OPENSSL_INIT_set_config_filename(OPENSSL_INIT_SETTINGS *settings,
                                       const char *config_file)
 {
     free(settings->config_name);
     settings->config_name = config_file == NULL ? NULL : strdup(config_file);
 }
+#endif
 
 void OPENSSL_INIT_free(OPENSSL_INIT_SETTINGS *settings)
 {

include/openssl/crypto.h

@@ -565,8 +565,10 @@ void OPENSSL_thread_stop(void);
 
 /* Low-level control of initialization */
 OPENSSL_INIT_SETTINGS *OPENSSL_INIT_new(void);
+#ifndef OPENSSL_NO_STDIO
 void OPENSSL_INIT_set_config_filename(OPENSSL_INIT_SETTINGS *settings,
                                       const char *config_file);
+#endif
 void OPENSSL_INIT_free(OPENSSL_INIT_SETTINGS *settings);
 
 /* BEGIN ERROR CODES */