[compiler-rt] [test] Remove an unintended grep parameter

This parameter seems unintentional here; we're trying to grep
the input on stdin, from the earlier stage in the pipeline.

Since a recent update on Github Actions runners, the previous
form (grepping a file, while piping in data on stdin) would fail
running the test, with the test runner Python script throwing
an exception when evaluating it:

      File "D:\a\llvm-mingw\llvm-mingw\llvm-project\llvm\utils\lit\lit\TestRunner.py", line 935, in _executeShCmd
        out = procs[i].stdout.read()
              ^^^^^^^^^^^^^^^^^^^^^^
      File "C:\hostedtoolcache\windows\Python\3.12.7\x64\Lib\encodings\cp1252.py", line 23, in decode
        return codecs.charmap_decode(input,self.errors,decoding_table)[0]
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    TypeError: a bytes-like object is required, not 'NoneType'

Author: mstorsjo

compiler-rt/test/asan/TestCases/Windows/delay_dbghelp.cpp

@@ -9,7 +9,7 @@
 // static build, there won't be any clang_rt DLLs.
 // RUN: not grep cl""ang_rt %t || \
 // RUN:   grep cl""ang_rt %t | xargs which | \
-// RUN:   xargs llvm-readobj --coff-imports | not grep dbghelp.dll %t
+// RUN:   xargs llvm-readobj --coff-imports | not grep dbghelp.dll
 
 extern "C" int puts(const char *);