sysfile_extractor: ignore exit code when removing directory at the end of the run.

On some systems the temporary directory may still be "busy" after WA is
don't with it. Since it's just an empty dir and it will be reused on the
subsequent runs; do check if rm -rf succeeded.

wlauto/instrumentation/misc/__init__.py

@@ -173,7 +173,8 @@ class SysfsExtractor(Instrument):
             except (DeviceError, CalledProcessError):
                 # assume a directory but not mount point
                 pass
-            self.device.execute('rm -rf {}'.format(self.tmpfs_mount_point), as_root=True)
+            self.device.execute('rm -rf {}'.format(self.tmpfs_mount_point),
+                                as_root=True, check_exit_code=False)
 
     def validate(self):
         if not self.tmpfs_mount_point:  # pylint: disable=access-member-before-definition