Fix problem that causes make dist to barf

This commit was SVN r24773.

ompi/include/Makefile.am

@@ -97,5 +97,5 @@ endif
 # Remove the auto-generated mpi-ext.h file
 # Since there is no mpi-ext.h.in, autogen does not know to cleanup this file.
 distclean-local:
-	rm -f mpi-ext.h mpicxx-ext.h mpif-ext.h mpif90-ext.h
+	rm -f mpi-ext.h mpicxx-ext.h mpif-ext.h mpif90-ext.f90