Don't compile GPU code with -fopenmp

Author: stephenchouca

src/codegen/module.cpp

@@ -132,12 +132,12 @@ string Module::compile() {
  cc = util::getFromEnv(target.compiler_env, target.compiler);
  cflags = util::getFromEnv("TACO_CFLAGS",
  "-O3 -ffast-math -std=c99") + " -shared -fPIC";
+#if USE_OPENMP
+ cflags += " -fopenmp";
+#endif
  file_ending = ".c";
  shims_file = "";
  }
-#if USE_OPENMP
- cflags += " -fopenmp";
-#endif
 
  string cmd = cc + " " + cflags + " " +
  prefix + file_ending + " " + shims_file + " " +