romio build failure on OpenBSD-5.7

[PHHargrove]

Just wanted to make a record of this other than the devel list posting.

As described in more detail in https://www.open-mpi.org/community/lists/devel/2015/05/17449.php OpenBSD-5.7 cannot build the romio version embedded in Open MPI v1.8, v1.10 or v2.0.
The problem, not present in OpenBSD-5.6 and earlier, relates to struct statfs which is not defined as romio expects:

/home/phargrov/OMPI/openmpi-1.8.6rc1-openbsd5-amd64/openmpi-1.8.6rc1/ompi/mca/io/romio/romio/adio/common/ad_fstype.c: In function 'ADIO_FileSysType_fncall': 
/home/phargrov/OMPI/openmpi-1.8.6rc1-openbsd5-amd64/openmpi-1.8.6rc1/ompi/mca/io/romio/romio/adio/common/ad_fstype.c:374: error: 'struct statfs' has no member named 'f_type' 
/home/phargrov/OMPI/openmpi-1.8.6rc1-openbsd5-amd64/openmpi-1.8.6rc1/ompi/mca/io/romio/romio/adio/common/ad_fstype.c:398: error: 'struct statfs' has no member named 'f_type' 
/home/phargrov/OMPI/openmpi-1.8.6rc1-openbsd5-amd64/openmpi-1.8.6rc1/ompi/mca/io/romio/romio/adio/common/ad_fstype.c:419: error: 'struct statfs' has no member named 'f_type' 
*** Error 1 in ompi/mca/io/romio/romio (Makefile:3335 'adio/common/ad_fstype.lo') 

As of the current mpich-3.2 there does not appear to be any upstream fix.