qcow2: Replace align_offset() with ROUND_UP()

qcow2: Replace align_offset() with ROUND_UP()

The align_offset() function is equivalent to the ROUND_UP() macro so
there's no need to use the former. The ROUND_UP() name is also a bit
more explicit.

This patch uses ROUND_UP() instead of the slower QEMU_ALIGN_UP()
because align_offset() already requires that the second parameter is a
power of two.

Signed-off-by: Alberto Garcia <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Message-id: 20180215131008[email protected]
Signed-off-by: Max Reitz <[email protected]>