Coverity issue with coll_base_reduce (CID 1435267)

[jsquyres]

@mkurnosov your name came up in git blame as the committer for 177c6ce, so you're getting tagged. 😉

Coverity found the following problem, which sounds kinda serious:

*** CID 1435267:  Uninitialized variables  (UNINIT)
/ompi/mca/coll/base/coll_base_reduce.c: 1032 in ompi_coll_base_reduce_intra_redscat_gather()
1026                                             MPI_STATUS_IGNORE));
1027                     if (MPI_SUCCESS != err) { goto cleanup_and_return; }
1028                     vrank = 0;
1029     
1030                 } else if (vrank == 0) {
1031                     /* Send a data to the root */
   CID 1435267:  Uninitialized variables  (UNINIT)
   Using uninitialized value "*rcount" when calling "*mca_pml.pml_send".
1032                     err = MCA_PML_CALL(send(rbuf, rcount[nsteps - 1], dtype, root,
1033                                             MCA_COLL_BASE_TAG_REDUCE,
1034                                             MCA_PML_BASE_SEND_STANDARD, comm));
1035                     if (MPI_SUCCESS != err) { goto cleanup_and_return; }
1036                     vrank = -1;
1037                 }

Can you please have a look and determine if this is a real issue? Thanks!

[jsquyres]

This has been fixed.