Update help documentation for -s logger option

Author: j-c-cook

can/logger.py

@@ -170,8 +170,8 @@ def main() -> None:
         "--file_size",
         dest="file_size",
         type=int,
-        help="Maximum file size in bytes. Rotate log file when size threshold "
-        "is reached.",
+        help="Maximum file size in bytes (or for the case of blf, maximum buffer size before compression and flush to "
+        "file). Rotate log file when size threshold is reached.",
         default=None,
     )