Fix test

Author: s-perron

clang/test/Driver/dxc_fspv_extension.hlsl

@@ -16,9 +16,9 @@
 
 // Check for the error message if the extension name is not properly formed.
 // RUN: not %clang_dxc -spirv -Tlib_6_7 -### %s -fspv-extension=KHR_BAD -fspv-extension=TEST1 -fspv-extension=SPV_GOOD -fspv-extension=TEST2 2>&1 | FileCheck %s -check-prefix=FAIL
-// FAIL: invalid value 'KHR_BAD' in '-fspv_extension'
-// FAIL: invalid value 'TEST1' in '-fspv_extension'
-// FAIL: invalid value 'TEST2' in '-fspv_extension'
+// FAIL: invalid value 'KHR_BAD' in '-fspv-extension'
+// FAIL: invalid value 'TEST1' in '-fspv-extension'
+// FAIL: invalid value 'TEST2' in '-fspv-extension'
 
 // If targeting DXIL, the `-spirv-ext` should not be passed to the backend.
 // RUN: %clang_dxc -Tlib_6_7 -### %s 2>&1 | FileCheck %s -check-prefix=DXIL