tests/functional/ppc/test_amiga: Fix issues reported by pylint and flake8

Pylint complains about unused variable "tar_name" and a missing "check"
for subprocess.run(), and flake8 suggest a second empty line after the
class. While we're at it, also remove the unused "timeout" class variable
(that was only necessary for the avocado framework which we don't use
anymore).

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20251119082636.43286-10-thuth@redhat.com>

tests/functional/ppc/test_amiga.py

@@ -15,8 +15,6 @@ from qemu_test import wait_for_console_pattern
 
 class AmigaOneMachine(QemuSystemTest):
 
-    timeout = 90
-
     ASSET_IMAGE = Asset(
         ('https://www.hyperion-entertainment.com/index.php/'
          'downloads?view=download&format=raw&file=25'),
@@ -25,19 +23,19 @@ class AmigaOneMachine(QemuSystemTest):
     def test_ppc_amigaone(self):
         self.require_accelerator("tcg")
         self.set_machine('amigaone')
-        tar_name = 'A1Firmware_Floppy_05-Mar-2005.zip'
         self.archive_extract(self.ASSET_IMAGE, format="zip")
         bios = self.scratch_file("u-boot-amigaone.bin")
         with open(bios, "wb") as bios_fh:
             subprocess.run(['tail', '-c', '524288',
                             self.scratch_file("floppy_edition",
                                               "updater.image")],
-                           stdout=bios_fh)
+                           stdout=bios_fh, check=True)
 
         self.vm.set_console()
         self.vm.add_args('-bios', bios)
         self.vm.launch()
         wait_for_console_pattern(self, 'FLASH:')
 
+
 if __name__ == '__main__':
     QemuSystemTest.main()