bb/ui/hob: fix package only build

Use the models new get_selected_pn method to return a list of PN's for the
selected items and pass that for a package only build, rather than passing
a list of package names (which buildTargets can't handle).

Fixes [YOCTO #1385]

Signed-off-by: Joshua Lock <josh@linux.intel.com>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>

bitbake/lib/bb/ui/hob.py

@@ -174,6 +174,7 @@ def image_changed_cb(self, combo):
             self.toggle_package(path, model, image=True)
             if len(userp):
                 self.model.set_selected_packages(userp)
+            self.selected_image = model[path][self.model.COL_NAME]
 
     def reload_triggered_cb(self, handler, image, packages):
         if image:
@@ -451,7 +452,7 @@ def bake_clicked_cb(self, button):
 
             self.handler.build_image(image_name, self.configurator)
         else:
-            self.handler.build_packages(rep.allpkgs.split(" "))
+            self.handler.build_packages(self.model.get_selected_pn())
 
         self.nb.set_current_page(1)