nacl_io: Remove the direct syscall intercept for 'remove'

This is no longer needed as the underlying syscalls
unlink/rmdir and both intercepted at the IRT level.  I
believe this was overlooked when we fixed:
https://code.google.com/p/nativeclient/issues/detail?id=3709

This should fix the recent lua5.2 failures on the
naclports waterfall.

CQ_EXTRA_TRYBOTS=tryserver.chromium.linux:linux_nacl_sdk;tryserver.chromium.mac:mac_nacl_sdk;tryserver.chromium.win:win_nacl_sdk
BUG=487701

Review URL: https://codereview.chromium.org/1136953014

Cr-Commit-Position: refs/heads/master@{#329871}

native_client_sdk/src/libraries/nacl_io/library.dsc

@@ -81,7 +81,6 @@
         "syscalls/pipe.c",
         "syscalls/poll.c",
         "syscalls/realpath.c",
-        "syscalls/remove.c",
         "syscalls/rename.c",
         "syscalls/select.c",
         "syscalls/sigaction.c",

native_client_sdk/src/libraries/nacl_io/syscalls/remove.c

-/* Copyright (c) 2013 The Chromium Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file. */
-
-#include "nacl_io/kernel_intercept.h"
-#include "nacl_io/kernel_wrap.h"
-
-#if defined(__GLIBC__) && defined(__native_client__)
-// Glibc's remove(3) and unlink(2) entry points are not yet hooked up
-// to the lower level IRT interfaces.  Therefore the only way to intercept
-// these calls is to override them here.
-// TODO(sbc): remove this once glibc plumbing is in place for remove/unlink
-
-int remove(const char* path) {
-  return ki_remove(path);
-}
-#endif

native_client_sdk/src/tests/nacl_io_test/kernel_wrap_test.cc

@@ -510,14 +510,13 @@ TEST_F(KernelWrapTest, readlink) {
   ASSERT_EQ(kDummyErrno, errno);
 }
 
-#ifdef __GLIBC__
-// Under newlib there is no remove syscall.  Instead it is implemented
-// in terms of unlink()/rmdir().
 TEST_F(KernelWrapTest, remove) {
-  EXPECT_CALL(mock, remove(kDummyConstChar)).WillOnce(Return(-1));
+  // The remove syscall is not directly intercepted. Instead it is implemented
+  // in terms of unlink()/rmdir().
+  EXPECT_CALL(mock, unlink(kDummyConstChar))
+       .WillOnce(DoAll(SetErrno(kDummyErrno), Return(-1)));
   EXPECT_EQ(-1, remove(kDummyConstChar));
 }
-#endif
 
 TEST_F(KernelWrapTest, rename) {
   EXPECT_CALL(mock, rename(kDummyConstChar, kDummyConstChar2))