Replace use of deprecated C Standard library headers in C++ code.

Change-Id: I9fa6630c7e4bdb2897df34d417635d8c7d8253bc
Signed-off-by: Tyler Chatow <tchatow@gmail.com>
diff --git a/aos/ipc_lib/signalfd.cc b/aos/ipc_lib/signalfd.cc
index 3689b7e..f23d0be 100644
--- a/aos/ipc_lib/signalfd.cc
+++ b/aos/ipc_lib/signalfd.cc
@@ -1,7 +1,8 @@
 #include "aos/ipc_lib/signalfd.h"
 
-#include <signal.h>
 #include <sys/types.h>
+
+#include <csignal>
 #if __has_feature(memory_sanitizer)
 #include <sanitizer/msan_interface.h>
 #endif