[hwasan] Remove --check-prefix=CHECK (NFC)
-// RUN: %clangxx_hwasan -O0 %s -o %t && not %env_hwasan_opts=halt_on_error=0 %run %t 2>&1 | FileCheck %s --check-prefix=CHECK
+// RUN: %clangxx_hwasan -O0 %s -o %t && not %env_hwasan_opts=halt_on_error=0 %run %t 2>&1 | FileCheck %s
// REQUIRES: stable-runtime
#include <stdlib.h>
