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>

lib/io.c

@@ -534,7 +534,9 @@ static int do_rollback = 0;
 static char * rollback_data;
 static int rollback_blocksize;
 
-void init_rollback_file (char * rollback_file, int *blocksize, FILE * log) {
+void init_rollback_file (char * rollback_file, unsigned int *blocksize,
+			 FILE * log)
+{
     char * string;
     struct stat buf;