NaCl: Fix nacl_io library to build with -Wstrict-prototypes

native_client_sdk/src/libraries/nacl_io/h_errno.c

Index: native_client_sdk/src/libraries/nacl_io/h_errno.c
diff --git a/native_client_sdk/src/libraries/nacl_io/h_errno.c b/native_client_sdk/src/libraries/nacl_io/h_errno.c
index 114878dbbd14d6d740350a06608d8428c86511fc..9d5ce6e24b9caf84660b3bda9c3838b4af6eacef 100644
--- a/native_client_sdk/src/libraries/nacl_io/h_errno.c
+++ b/native_client_sdk/src/libraries/nacl_io/h_errno.c
@@ -12,11 +12,11 @@
 static pthread_key_t s_h_errno_key;
 static pthread_once_t s_h_errno_once = PTHREAD_ONCE_INIT;
 
-static void __h_errno_create() {
+static void __h_errno_create(void) {
   pthread_key_create(&s_h_errno_key, NULL);
 }
 
-int *__h_errno_location() {
+int *__h_errno_location(void) {
   int* h_errno_ptr;
   pthread_once(&s_h_errno_once, __h_errno_create);
   h_errno_ptr = (int *) pthread_getspecific(s_h_errno_key);
@@ -31,7 +31,7 @@ int *__h_errno_location() {
 }
 
 #if defined(__BIONIC__)
-int *__get_h_errno() {
+int *__get_h_errno(void) {
   return __h_errno_location();
 }
 #endif