Minor bug fix for zombies and added extern for MAM main structures

Codes/malleability/malleabilityDataStructures.c

 #include "malleabilityDataStructures.h"
 
+malleability_config_t *mall_conf = NULL;
+malleability_t *mall = NULL;
 int state = MALL_UNRESERVED;
 
 /*

Codes/malleability/malleabilityDataStructures.h

@@ -54,8 +54,8 @@ typedef struct {
 } malleability_t;
 
 /* --- VARIABLES --- */
-malleability_config_t *mall_conf;
-malleability_t *mall;
+extern malleability_config_t *mall_conf;
+extern malleability_t *mall;
 extern int state;
 
 /* --- FUNCTIONS --- */

Codes/malleability/malleabilityZombies.c

@@ -94,7 +94,7 @@ void MAM_I_zombies_split() {
   MPI_Comm_split(mall->original_comm, color, myId, &new_original_comm);
 
   if(mall->original_comm != MPI_COMM_WORLD) MPI_Comm_free(&mall->original_comm);
-  MPI_Comm_set_name(new_original_comm, "MAM_ORIGINAL");
+  if(new_original_comm != MPI_COMM_NULL) MPI_Comm_set_name(new_original_comm, "MAM_ORIGINAL");
   mall->original_comm = new_original_comm;
 }