man: Revert my MPI_File_iwrite_shared manpage change.

This reverts commit 2226cdb3dacd21dcf7e9836db57ddb9d7936ac43
and                 d9c93c9f5d71c7e8cecedb2bed39d8d33029baf1.

Because Gilles' b17c89c1 committed a few hours ago has the same change,
my RP branch had a conflict.

ompi/mpi/man/man3/MPI_File_iwrite_shared.3in

@@ -15,14 +15,14 @@
 .nf
 C Syntax
     #include <mpi.h>
-    int MPI_File_iwrite_shared(MPI_File \fIfh\fP, const void \fI*buf\fP, int \fIcount\fP,
-    	      MPI_Datatype \fIdatatype\fP, MPI_Request \fI*request\fP)
+    int MPI_File_(MPI_File \fIfh\fP, const void \fI*buf\fP, int \fIcount\fP, MPI_Datatype
+    	      \fIdatatype\fP, MPI_Request \fI*request\fP)
 
 .fi
 .SH Fortran Syntax
 .nf
     INCLUDE 'mpif.h'
-    MPI_FILE_IWRITE_SHARED(\fIFH\fP, \fIBUF\fP, \fICOUNT\fP, \fIDATATYPE\fP, \fIREQUEST\fP,\fI IERROR\fP)
+    MPI_File_(\fIFH\fP, \fIBUF\fP, \fICOUNT\fP, \fIDATATYPE\fP, \fIREQUEST\fP,\fI IERROR\fP)
 		<type>		BUF(*)
         	INTEGER		FH, COUNT, DATATYPE, REQUEST, IERROR