[clang] Fix a new test to not write temp files to the git repository

Author: gribozavr

clang/test/OpenMP/dispatch_unsupported.c

@@ -1,6 +1,6 @@
-// RUN: %clang_cc1 -emit-llvm -fopenmp -disable-llvm-passes %s -verify=expected
+// RUN: %clang_cc1 -emit-llvm -fopenmp -disable-llvm-passes %s -o /dev/null -verify=expected
 
-// expected-error@+2 {{cannot compile this OpenMP dispatch directive yet}} 
+// expected-error@+2 {{cannot compile this OpenMP dispatch directive yet}}
 void a(){
     #pragma omp dispatch
     a();