kvm tools: Fix qcow1_read_cluster() return value on error

The qcow1_read_cluster() returns negative number on error but the return value
type is unsigned. Fix that up and also fix the call-site in qcow1_read_sector()
to deal with negative return value properly.

Signed-off-by: Pekka Enberg <penberg@kernel.org>
1 file changed