Make check-lit tests respect LLVM_LIT_TOOLS_DIR

Differential Revision: https://reviews.llvm.org/D40520

llvm-svn: 319329
diff --git a/llvm/utils/lit/tests/shtest-format.py b/llvm/utils/lit/tests/shtest-format.py
index 37e3e1c..94d74e3 100644
--- a/llvm/utils/lit/tests/shtest-format.py
+++ b/llvm/utils/lit/tests/shtest-format.py
@@ -16,7 +16,7 @@
 # CHECK-NEXT: line 2: failed test output on stdout
 # CHECK: Command Output (stderr):
 # CHECK-NEXT: --
-# CHECK-NEXT: cat: does-not-exist: No such file or directory
+# CHECK-NEXT: cat{{(\.exe)?}}: does-not-exist: No such file or directory
 # CHECK: --
 
 # CHECK: FAIL: shtest-format :: external_shell/fail_with_bad_encoding.txt