The ui device llseek had a mistake with SEEK_END and did
not fully follow seek semantics. Correct all this by
using a kernel supplied function for fixed size devices.
Cc: Al Viro <viro@ZenIV.linux.org.uk> Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Dean Luick <dean.luick@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>