coll/spacc: silence more coverity warnings in mca_coll_spacc_allreduce_intra_redscat_allgather()

Signed-off-by: Gilles Gouaillardet <gilles@rist.or.jp>

ompi/mca/coll/spacc/coll_spacc_allreduce.c

@@ -281,7 +281,6 @@ int mca_coll_spacc_allreduce_intra_redscat_allgather(
             wsize = rcount[step];
             step++;
         }
-    }
         /*
          * Assertion: each process has 1 / p' of the total reduction result:
          * rcount[nsteps - 1] elements in the rbuf[rindex[nsteps - 1], ...].
@@ -295,8 +294,7 @@ int mca_coll_spacc_allreduce_intra_redscat_allgather(
          * to recursive doubling (previous step).
          */
 
-    if (vrank != -1) {
+        step--;
-        step = nsteps - 1; /* step = ilog2(p') - 1 */
 
         for (int mask = nprocs_pof2 >> 1; mask > 0; mask >>= 1) {
             int vdest = vrank ^ mask;