ext4: miscellaneous partial cluster cleanups
ext4: miscellaneous partial cluster cleanups

Add some casts and rearrange a few statements for improved readability.
Some code can also be simplified and made more readable if we set
partial_cluster to 0 rather than to a negative value when we can tell
we've hit the left edge of the punched region.

Signed-off-by: Eric Whitney <ba5ac80d1fb5812604686391b77cc69908a724fa@gmail.com>
Signed-off-by: Theodore Ts'o <4ed386e0495d3e109932df055831d9ec2f824927@mit.edu>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs