Ensure syscall functions are consistently prefixed with "NaClSys"

src/trusted/service_runtime/nacl_syscall_common.h

 /*
  * Copyright (c) 2012 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /*
  * NaCl service run-time, non-platform specific system call helper routines.
  */
 
@@ skipping 15 matching lines @@
 struct NaClDesc;
 struct NaClImcMsgHdr;
 struct nacl_abi_stat;
 
 int32_t NaClSysNotImplementedDecoder(struct NaClAppThread *natp);
 
 void NaClAddSyscall(int num, int32_t (*fn)(struct NaClAppThread *));
 
 int32_t NaClSysNull(struct NaClAppThread *natp);
 
-int32_t NaClSetBreak(struct NaClAppThread *natp,
-                     uintptr_t            new_break);
+int32_t NaClSysBrk(struct NaClAppThread *natp,
+                   uintptr_t            new_break);
 
 int NaClHighResolutionTimerEnabled(void);
 
 int32_t NaClOpenAclCheck(struct NaClApp *nap,
                          char const     *path,
                          int            flags,
                          int            mode);
 
 int32_t NaClStatAclCheck(struct NaClApp *nap,
                          char const     *path);
@@ skipping 227 matching lines @@
 
 int32_t NaClSysExceptionClearFlag(struct NaClAppThread *natp);
 
 int32_t NaClSysTestInfoLeak(struct NaClAppThread *natp);
 
 int32_t NaClSysTestCrash(struct NaClAppThread *natp, int crash_type);
 
 EXTERN_C_END
 
 #endif  /* NATIVE_CLIENT_SERVICE_RUNTIME_NACL_SYSCALL_COMMON_H__ */