main: drop log file path check

Remove check that the log file path exists.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I8324ea847fd57de54ab1a9d252fd12a3ddafc4d8
diff --git a/main.cpp b/main.cpp
index 6dca309..477be66 100644
--- a/main.cpp
+++ b/main.cpp
@@ -71,8 +71,7 @@
         ->check(CLI::ExistingFile);
     app.add_option("-t,--tuning", tuningLoggingPath,
                    "Optional parameter to specify tuning logging path, and "
-                   "enable tuning")
-        ->check(CLI::ExistingFile);
+                   "enable tuning");
 
     CLI11_PARSE(app, argc, argv);