[PATCHES] Add gpfs.h to always build vfs_gpfs module

[Christof Schmitt]

On Sat, Jan 12, 2019 at 04:09:21AM +0000, jim via samba-technical wrote:
> Shouldn't you condition setting gpfs_h_dir to third_party/gpfs on gpfs.h 
> not being found in /usr/lpp/mmfs/include/ and/or directory 
> /usr/lpp/mmfs/include/ does not exist?
> Then the detection will function properly if gpfs is installed on the 
> system.

Yes, that makes more sense. Also having the configure option explicitly
overrride any defaults. I think a found a better way to put this in waf,
updated patch to follow.

Christof