Update usage screen wording in section for --outfile-check-dir

Fixes #3464

src/usage.c

@@ -73,7 +73,7 @@ static const char *const USAGE_BIG_PRE_HASHMODES[] =
   "     --debug-mode               | Num  | Defines the debug mode (hybrid only by using rules)  | --debug-mode=4",
   "     --debug-file               | File | Output file for debugging rules                      | --debug-file=good.log",
   "     --induction-dir            | Dir  | Specify the induction directory to use for loopback  | --induction=inducts",
-  "     --outfile-check-dir        | Dir  | Specify the outfile directory to monitor for plains  | --outfile-check-dir=x",
+  "     --outfile-check-dir        | Dir  | Specify the directory to monitor 3rd party outfiles  | --outfile-check-dir=x",
   "     --logfile-disable          |      | Disable the logfile                                  |",
   "     --hccapx-message-pair      | Num  | Load only message pairs from hccapx matching X       | --hccapx-message-pair=2",
   "     --nonce-error-corrections  | Num  | The BF size range to replace AP's nonce last bytes   | --nonce-error-corrections=16",