test: fix negative test case

Add missing -### to the driver to ensure that we dont try to run the
actual command.  The host may not support the IAS.  Should fix the SCEI
buildbots.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@306123 91177308-0d34-0410-b5e6-96231b3b80d8

test/Driver/nozlibcompress.c

 // REQUIRES: nozlib
 
-// RUN: %clang -fintegrated-as -gz -c %s 2>&1 | FileCheck %s -check-prefix CHECK-WARN
-// RUN: %clang -fintegrated-as -gz=none -c %s 2>&1 | FileCheck -allow-empty -check-prefix CHECK-NOWARN %s
+// RUN: %clang -### -fintegrated-as -gz -c %s 2>&1 | FileCheck %s -check-prefix CHECK-WARN
+// RUN: %clang -### -fintegrated-as -gz=none -c %s 2>&1 | FileCheck -allow-empty -check-prefix CHECK-NOWARN %s
 
 // CHECK-WARN: warning: cannot compress debug sections (zlib not installed)
 // CHECK-NOWARN-NOT: warning: cannot compress debug sections (zlib not installed)