tests: Fix argparse description in simple_binary_run.py

Change-Id: I3a86cf9e3326a06f442315d2510c5aec326af358
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/51451
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

tests/gem5/configs/simple_binary_run.py

@@ -43,8 +43,7 @@ from gem5.components.processors.cpu_types import CPUTypes
 import argparse
 
 parser = argparse.ArgumentParser(
-    description="A script to run the gem5 boot test. This test boots the "
-    "linux kernel."
+    description="A gem5 script for running simple binaries in SE mode."
 )
 
 parser.add_argument(