Merge pull request #2806 from jjhursey/fix/ibm/aint-diff-type

Fix a minor error at MPI_AINT_DIFF.

ompi/include/mpi.h.in

@@ -19,6 +19,7 @@
  * Copyright (c) 2015      University of Houston. All rights reserved.
  * Copyright (c) 2015      Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
+ * Copyright (c) 2017      IBM Corporation.  All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -1182,7 +1183,7 @@ OMPI_DECLSPEC extern MPI_Fint *MPI_F_STATUSES_IGNORE;
 #define MPI_Aint_add(base, disp) ((MPI_Aint) ((char *) (base) + (disp)))
 #define MPI_Aint_diff(addr1, addr2) ((MPI_Aint) ((char *) (addr1) - (char *) (addr2)))
 #define PMPI_Aint_add(base, disp) MPI_Aint_add(base, disp)
-#define PMPI_Aint_diff(addr1, addr2) PMPI_Aint_diff(addr1, addr2)
+#define PMPI_Aint_diff(addr1, addr2) MPI_Aint_diff(addr1, addr2)
 
 /*
  * MPI API