osi_UFSOpen returns struct osi_file *

osi_UFSOpen returns struct osi_file *

The osi_UFSOpen function always returns a (struct osi_file *). Fix
the code to reflect this, rather than casting to and from (void *).

Change-Id: I3aa0bb17b547060671aa7045a8237b3926ec613f
Reviewed-on: http://gerrit.openafs.org/851
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>