[NaCl SDK] Remove syscalls wrappers for chmod and unlink.

native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc

Index: native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc b/native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc
index e992c2784b6fc458991d2607d47a1eed796270e4..f560d3b125705959f41e69ed960a139222c8e6b6 100644
--- a/native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc
+++ b/native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.cc
@@ -272,6 +272,11 @@ static void assign_real_pointers() {
   if (!REAL(func))          \
     assign_real_pointers();
 
+#define CHECK_REAL_NOSYS(func)  \
+  CHECK_REAL(func)              \
+  if (!REAL(func))              \
+    return ENOSYS;
+
 // "real" functions, i.e. the unwrapped original functions.
 
 int _real_close(int fd) {
@@ -354,6 +359,11 @@ int _real_write(int fd, const void* buf, size_t count, size_t* nwrote) {
   return REAL(write)(fd, buf, count, nwrote);
 }
 
+int _real_getcwd(char* pathname, size_t len) {
+  CHECK_REAL_NOSYS(getcwd);
+  return REAL(getcwd)(pathname, len);
+}
+
 static bool s_wrapped = false;
 
 void kernel_wrap_init() {