Fix a build error with OpenMPI 1.4.x

The function ADIOI_PLFS_Feature() shouldn't be defined when
compiling PLFS with OpenMPI 1.4.x.
Merge pull request #215 from zhang-jingwang/master

Fix a build error with OpenMPI v1.4.3
Merge branch 'master' of github.com:plfs/plfs-core into 2.4dev