fix [#33792] Accessing a bmesh object created by from_object crashes blender

Issue was customdata wasnt being initialized for layers in the destination BMesh but not in the source data.


git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@53657 954f8c5b-7b00-dc11-b283-0030488c597c