Only call gpt under macOS

scripts/wk/hw/diags.py

@@ -6,6 +6,7 @@ import atexit
 import logging
 import os
 import pathlib
+import platform
 import subprocess
 import time
 
@@ -281,6 +282,7 @@ class State():
         for test in disk.tests:
           _f.write(f'\n{test.name}:\n')
           _f.write('\n'.join(debug.generate_object_report(test, indent=1)))
+      if platform.system() == 'Darwin':
         cmd = [(
           f'sudo gpt -r show "{disk.path}"'
           f' >> {debug_dir}/gpt_{disk.path.name}.info'