Revert of Introduce sys_sigprocmask and sys_sigaction.

sandbox/linux/seccomp-bpf/die.cc

Index: sandbox/linux/seccomp-bpf/die.cc
diff --git a/sandbox/linux/seccomp-bpf/die.cc b/sandbox/linux/seccomp-bpf/die.cc
index 3baf1f13d9e5272d268b06f312bb17cf055fd23d..777c9d1139298f46d78bb1ef0a97667b48414015 100644
--- a/sandbox/linux/seccomp-bpf/die.cc
+++ b/sandbox/linux/seccomp-bpf/die.cc
@@ -16,8 +16,6 @@
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "sandbox/linux/seccomp-bpf/syscall.h"
-#include "sandbox/linux/services/syscall_wrappers.h"
-#include "sandbox/linux/system_headers/linux_signal.h"
 
 namespace sandbox {
 
@@ -34,10 +32,7 @@
   // to a defined state; but we have not way to verify whether we actually
   // succeeded in doing so. Nonetheless, triggering a fatal signal could help
   // us terminate.
-  struct sigaction sa = {};
-  sa.sa_handler = LINUX_SIG_DFL;
-  sa.sa_flags = LINUX_SA_RESTART;
-  sys_sigaction(LINUX_SIGSEGV, &sa, nullptr);
+  signal(SIGSEGV, SIG_DFL);
   Syscall::Call(__NR_prctl, PR_SET_DUMPABLE, (void*)0, (void*)0, (void*)0);
   if (*(volatile char*)0) {
   }