ADIOS: Resize the write buffer to the known required size.

This change now requires ADIOS/master

Change-Id: Id7d72d5f276dd22476714213df1486ba7ead6a32
ADIOS: Update FindADIOS to match upstream

Change-Id: I121cdd04a5a529696e30263a78dae00fbd5ee8a4
Merge topic 'adios-buffer-resizing' into master

3c8af892 ADIOS: Update FindADIOS to match upstream
874279a0 ADIOS: Resize the write buffer to the known required size.