Auto merge of #2623 - alexcrichton:nfs-lol-no, r=brson
authorbors <bors@rust-lang.org>
Fri, 29 Apr 2016 17:15:47 +0000 (10:15 -0700)
committerbors <bors@rust-lang.org>
Fri, 29 Apr 2016 17:15:47 +0000 (10:15 -0700)
Don't use flock on NFS mounts

Completely skip file locking when we detect an NFS mount via `statfs`.

Closes #2615


Trivial merge