This commit fixes an ordering bug in the code that keeps track of all
attached memory windows. The code is intended to keep the memory
regions sorted but was often inserting at the wrong index. Thanks to
Christoph Niethammer for reporting the issue. The reproducer will be
added to nightly MTT testing.
Fixesopen-mpi/ompi#2012
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>