staging/lustre: Drop FS_HAS_FIEMAP compat macro

FS_HAS_FIEMAP was some sort of old RHEL5 construct that's not
really important anymore

Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>