NetworkManager: fix dnsmasq interaction for ad-hoc networks

Fixes #7593 (NM can't find the dnsmasq binary); the NM expression is missing
dnsmasq in its buildInputs, so configure can't find it.

Also creates /var/lib/misc which dnsmasq expects to exist, because it puts
dnsmasq.leases there.

nixos/modules/services/networking/networkmanager.nix

@@ -6,7 +6,8 @@ with lib;
 let
   cfg = config.networking.networkmanager;
 
-  stateDirs = "/var/lib/NetworkManager /var/lib/dhclient";
+  # /var/lib/misc is for dnsmasq.leases.
+  stateDirs = "/var/lib/NetworkManager /var/lib/dhclient /var/lib/misc";
 
   configFile = writeText "NetworkManager.conf" ''
     [main]

pkgs/tools/networking/network-manager/default.nix

@@ -45,7 +45,7 @@ stdenv.mkDerivation rec {
   ];
 
   buildInputs = [ wirelesstools udev libnl libuuid polkit ppp libndp
-                  xz bluez5 gobjectIntrospection modemmanager readline newt libsoup ];
+                  xz bluez5 dnsmasq gobjectIntrospection modemmanager readline newt libsoup ];
 
   propagatedBuildInputs = [ dbus_glib gnutls libgcrypt ];