check_first_part_offset: update comment about why the command might'v…

…e failed

repos/system_upgrade/common/actors/checkfirstpartitionoffset/libraries/check_first_partition_offset.py

@@ -74,7 +74,7 @@ def check_first_partition_offset():
             if not is_ok:
                 problematic_devices.append(device)
         except CalledProcessError:
-            # The disk is too small for grub, or the disk does not exists - therefore, grub.get_grub_devices lied
+            # The path does not point to an actual device, or the disk does not exists - grub.get_grub_devices lied?
             msg = 'Failed to check the offset of the first partition of the device {0}'
             raise StopActorExecutionError(msg.format(device))