Summary:
In order to get Watchman to recognize EdenFS mounted as NFS, we previously set
the f_mntfromname to be "edenfs". Unfortunately, Apple decided that when the
NFS server is accessed via a unix socket it would overwrite that and instead
use the path to the socket.
Digging in the source code, I did find that the f_fstypename can be overwritten
by calling fsctl with the right set of arguments. Thus, let's do just that.
Reviewed By: kmancini
Differential Revision: D28270605
fbshipit-source-id: f6be4e394d814806aa03ec3e82b8bc2faf364ea7