Include signal.h depending on HAVE_SIGNAL_H, not depending on __linux__
diff --git a/lib/cpp/test/SecurityFromBufferTest.cpp b/lib/cpp/test/SecurityFromBufferTest.cpp
index 72a4c2a..d275191 100644
--- a/lib/cpp/test/SecurityFromBufferTest.cpp
+++ b/lib/cpp/test/SecurityFromBufferTest.cpp
@@ -30,7 +30,7 @@
 #include <thrift/transport/TSSLSocket.h>
 #include <thrift/transport/TTransport.h>
 #include <vector>
-#ifdef __linux__
+#ifdef HAVE_SIGNAL_H
 #include <signal.h>
 #endif