revert change that shouldn't have been part of r28952

This commit was SVN r28953.

The following SVN revision numbers were found above:
  r28952 --> open-mpi/ompi@cb90a4a7fc

ompi/mca/coll/libnbc/nbc_internal.h

@@ -550,6 +550,10 @@ static inline void NBC_SchedCache_dictwipe(hb_tree *dict, int *size) {
   if(sendbuf == MPI_IN_PLACE) { \
     sendbuf = recvbuf; \
     inplace = 1; \
+  } else \
+  if(recvbuf == MPI_IN_PLACE) { \
+    recvbuf = sendbuf; \
+    inplace = 1; \
   } \
 }