Remove macro __linux__

Test: m netsim

Change-Id: I3df5c7a13141a672bf36a656880e7edc110adb03
diff --git a/src/netsim.cc b/src/netsim.cc
index 00e93ba..5b1f447 100644
--- a/src/netsim.cc
+++ b/src/netsim.cc
@@ -12,14 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <getopt.h>
-#if defined(__linux__)
 #include <execinfo.h>
+#include <getopt.h>
 #include <signal.h>
 #include <unistd.h>
 
 #include <cstdio>
-#endif
 
 #include "core/server.h"
 #ifdef NETSIM_ANDROID_EMULATOR
@@ -30,7 +28,6 @@
 
 // Wireless network simulator for android (and other) emulated devices.
 
-#if defined(__linux__)
 // Signal handler to print backtraces and then terminate the program.
 void SignalHandler(int sig) {
   size_t buffer_size = 20;  // Number of entries in that array.
@@ -48,12 +45,14 @@
   std::cerr << argv[0] << ": invalid option -- " << (char)c << "\n";
   std::cerr << "Try `" << argv[0] << " --help' for more information.\n";
 }
-#endif
 
 int main(int argc, char *argv[]) {
 #if defined(__linux__)
-  signal(SIGSEGV, SignalHandler);
+  std::cout << "Testing: __linux__ is defined" << std::endl;
 #endif
+
+  signal(SIGSEGV, SignalHandler);
+
   const char *kShortOpt = "s:dg";
   bool debug = false;
   bool grpc_startup = false;