[OpenMP] Fix tool tests 9475ed8

These were still passing because I did not clear all the test artifacts
in between so the old ones were still present after updating the test. I
forgot to update a lit substitution which failed on clean builds.

Author: boomanaiden154

openmp/runtime/test/lit.cfg

@@ -221,7 +221,7 @@ if config.has_ompt:
         # No such linker flag on Darwin.
         config.substitutions.append(("%no-as-needed-flag", ""))
     else:
-        config.substitutions.append(("%preload-tool", "env LD_PRELOAD=%T/tool.so"))
+        config.substitutions.append(("%preload-tool", "env LD_PRELOAD=%t.tool_dir/tool.so"))
         config.substitutions.append(("%no-as-needed-flag", "-Wl,--no-as-needed"))
 else:
     config.substitutions.append(("FileCheck", config.test_filecheck))