md/bitmap: separate out loading a bitmap from initialising the structures.
NeilBrown authored

dm makes this distinction between ->ctr and ->resume, so we need to
too.

Also get the new bitmap_load to clear out the bitmap first, as this is
most consistent with the dm suspend/resume approach
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
69e51b44