Prefer 'env not' over 'not env' in tests.

That way, lit's builtin 'env' command can be used for the 'env' bit.

Also it's clearer that way that the 'not' shouldn't cover 'env'
failures.

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@374749 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/clangd/test/log.test b/clangd/test/log.test
index 7f17f07..68d6d29 100644
--- a/clangd/test/log.test
+++ b/clangd/test/log.test
@@ -1,4 +1,4 @@
-# RUN: not env CLANGD_FLAGS=-index-file=no-such-index clangd -lit-test </dev/null 2>&1 >/dev/null | FileCheck %s
+# RUN: env CLANGD_FLAGS=-index-file=no-such-index not clangd -lit-test </dev/null 2>&1 >/dev/null | FileCheck %s
 CHECK: I[{{.*}}] clangd version {{.*}}
 CHECK: Working directory: {{.*}}
 CHECK: argv[0]: clangd