hcoll: Reorder checks for early return in initialization

Check for communicators that do not meet the criteria for hcoll setup
before initializing the hcoll library. This prevents crashes due to
e.g. MPI_COMM_SELF being created during business card exchange before
communication is ready.

Author: raffenet

src/mpid/common/hcoll/hcoll_init.c

@@ -132,27 +132,28 @@ int hcoll_comm_create(MPIR_Comm * comm_ptr, void *param)
 
     comm_ptr->hcoll_priv.is_hcoll_init = 0;
 
-    if (0 == hcoll_initialized) {
-        mpi_errno = hcoll_initialize();
-        MPIR_ERR_CHECK(mpi_errno);
+    if (0 == hcoll_enable) {
+        goto fn_exit;
     }
 
-    if (0 == hcoll_enable) {
+    num_ranks = comm_ptr->local_size;
+    if ((MPIR_COMM_KIND__INTRACOMM != comm_ptr->comm_kind) || (2 > num_ranks)
+        || comm_ptr->hierarchy_kind == MPIR_COMM_HIERARCHY_KIND__NODE_ROOTS
+        || comm_ptr->hierarchy_kind == MPIR_COMM_HIERARCHY_KIND__NODE) {
         goto fn_exit;
     }
 
+    if (0 == hcoll_initialized) {
+        mpi_errno = hcoll_initialize();
+        MPIR_ERR_CHECK(mpi_errno);
+    }
+
     if (MPIR_Process.comm_world == comm_ptr) {
         hcoll_comm_world_initialized = 1;
     }
     if (!hcoll_comm_world_initialized) {
         goto fn_exit;
     }
-    num_ranks = comm_ptr->local_size;
-    if ((MPIR_COMM_KIND__INTRACOMM != comm_ptr->comm_kind) || (2 > num_ranks)
-        || comm_ptr->hierarchy_kind == MPIR_COMM_HIERARCHY_KIND__NODE_ROOTS
-        || comm_ptr->hierarchy_kind == MPIR_COMM_HIERARCHY_KIND__NODE) {
-        goto fn_exit;
-    }
 
     comm_ptr->hcoll_priv.hcoll_context = hcoll_create_context((rte_grp_handle_t) comm_ptr);
     if (NULL == comm_ptr->hcoll_priv.hcoll_context) {