Remove useless dest of option in volume v1&v2

some "dest" argument is useless because they are
the same as the option name. So remove them.

Change-Id: Idd37e8816cf8b0833c94a5e741fdfe56602551f9

openstackclient/volume/v1/volume.py

@@ -175,7 +175,6 @@ class DeleteVolume(command.Command):
         )
         parser.add_argument(
             '--force',
-            dest='force',
             action='store_true',
             default=False,
             help=_('Attempt forced removal of volume(s), regardless of state '

openstackclient/volume/v2/volume.py

@@ -167,7 +167,6 @@ class DeleteVolume(command.Command):
         )
         parser.add_argument(
             "--force",
-            dest="force",
             action="store_true",
             default=False,
             help=_("Attempt forced removal of volume(s), regardless of state "

openstackclient/volume/v2/volume_type.py

@@ -47,14 +47,12 @@ class CreateVolumeType(command.ShowOne):
         public_group = parser.add_mutually_exclusive_group()
         public_group.add_argument(
             "--public",
-            dest="public",
             action="store_true",
             default=False,
             help=_("Volume type is accessible to the public"),
         )
         public_group.add_argument(
             "--private",
-            dest="private",
             action="store_true",
             default=False,
             help=_("Volume type is not accessible to the public"),