Fix xf86vmware fix

Moved xf86vmware fix into the overrides.nix file where and not in the
generated default.nix.
Merge branch 'fixVmwareFix' of git://github.com/Davorak/nixpkgs

The original fix modified a generated file instead of the
manually-maintained overrides file. Checked by inspection.

Signed-off-by: Shea Levy <shea@shealevy.com>