Staging: slicoss: Removal of unused macros in slicoss.c

This patch removes unused macro in slicoss.c as mentioned in TODO tasks.

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>