Merging sparse chunk can make sparse map block bigger than 4GiB,
that can't be covered by unsigned integer type. Fix this by
changing unsigned int to uint64_t type.
Test: sparse build
Bug: 162808120
Change-Id: Id4d3f88f9d531c25c3937c99b2c81efb915605ee
Signed-off-by: Hyeongseok Kim <hyeongseok@gmail.com>
Cc: hyeongseok.kim <hyeongseok.kim@lge.com>