reiserfsprogs: fix -Wpointer-sign warnings for blocksize and position

This patch fixes the following warnings:
pointer targets in passing argument 5 of ‘reiserfs_bin_search’ differ in signedness [-Wpointer-sign]
pointer targets in passing argument 2 of ‘init_rollback_file’ differ in signedness [-Wpointer-sign]

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
5 files changed