replace makeSearchPath tree-wise to take care of possible multiple outputs

nixos/modules/virtualisation/azure-agent.nix

@@ -42,7 +42,7 @@ let
 
       wrapProgram "$out/bin/waagent" \
           --prefix PYTHONPATH : $PYTHONPATH \
-          --prefix PATH : "${makeSearchPath "bin" runtimeDeps}"
+          --prefix PATH : "${makeBinPath runtimeDeps}"
     '';
   };
 

nixos/modules/virtualisation/virtualbox-guest.nix

@@ -66,7 +66,7 @@ in
 
     services.xserver.displayManager.sessionCommands =
       ''
-        PATH=${makeSearchPath "bin" [ pkgs.gnugrep pkgs.which pkgs.xorg.xorgserver.out ]}:$PATH \
+        PATH=${makeBinPath [ pkgs.gnugrep pkgs.which pkgs.xorg.xorgserver.out ]}:$PATH \
           ${kernel.virtualboxGuestAdditions}/bin/VBoxClient-all
       '';