Remove old hack meant to remove stale metadata.

There are several such mechanisms being employed elsewhere in blivet
and even in the lvm tools themselves. This should not be needed anymore.

blivet/formats/lvmpv.py

@@ -117,12 +117,6 @@ def _create(self, **kwargs):
 
         # Consider use of -Z|--zero
         # -f|--force or -y|--yes may be required
-
-        # lvm has issues with persistence of metadata, so here comes the
-        # hammer...
-        # XXX This format doesn't exist yet, so bypass the precondition checking
-        #     for destroy by calling _destroy directly.
-        DeviceFormat._destroy(self, **kwargs)
         blockdev.lvm.pvscan(self.device)
         blockdev.lvm.pvcreate(self.device, data_alignment=self.data_alignment)
         blockdev.lvm.pvscan(self.device)