UBI: rename MOVE_CANCEL_BITFLIPS to MOVE_TARGET_BITFLIPS

While looking at a problem reported by UBI around the PEB moving area I
noticed that the 'MOVE_CANCEL_BITFLIPS' is a bit inconsistent name and
'MOVE_TARGET_BITFLIPS' better - let's rename it.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

diff --cc drivers/mtd/ubi/eba.c
Simple merge

diff --cc drivers/mtd/ubi/ubi.h
Simple merge

diff --cc drivers/mtd/ubi/wl.c
Simple merge