Simplify login for officer user in tests

The same way it's done in other places. We also remove a useless
assignment.

spec/features/admin_spec.rb

@@ -47,8 +47,7 @@ describe "Admin" do
   end
 
   scenario "Access as poll officer is not authorized" do
-    create(:poll_officer, user: user)
-    login_as(user)
+    login_as(create(:poll_officer).user)
     visit admin_root_path
 
     expect(page).not_to have_current_path(admin_root_path)

spec/features/budget_polls/officing_spec.rb

@@ -5,13 +5,11 @@ describe "Budget Poll Officing" do
   scenario "Show sidebar menus if officer has shifts assigned" do
     booth = create(:poll_booth)
     booth_assignment = create(:poll_booth_assignment, booth: booth)
-
-    user = create(:user)
-    officer = create(:poll_officer, user: user)
+    officer = create(:poll_officer)
 
     create(:poll_shift, officer: officer, booth: booth, date: Date.current, task: :vote_collection)
 
-    login_as user
+    login_as officer.user
     visit officing_root_path
 
     expect(page).not_to have_content("You don't have officing shifts today")
@@ -32,10 +30,8 @@ describe "Budget Poll Officing" do
   end
 
   scenario "Do not show sidebar menus if officer has no shifts assigned" do
-    user = create(:user)
-    officer = create(:poll_officer, user: user)
+    login_as(create(:poll_officer).user)
 
-    login_as user
     visit officing_root_path
 
     expect(page).to have_content("You don't have officing shifts today")

spec/features/officing_spec.rb

@@ -129,10 +129,8 @@ describe "Poll Officing" do
     booth = create(:poll_booth)
     booth_assignment = create(:poll_booth_assignment, poll: poll, booth: booth)
 
-    user1 = create(:user)
-    user2 = create(:user)
-    officer1 = create(:poll_officer, user: user1)
-    officer2 = create(:poll_officer, user: user2)
+    officer1 = create(:poll_officer)
+    officer2 = create(:poll_officer)
 
     create(:poll_shift, officer: officer1, booth: booth, date: Date.current, task: :vote_collection)
     create(:poll_shift, officer: officer2, booth: booth, date: Date.current, task: :vote_collection)
@@ -141,12 +139,12 @@ describe "Poll Officing" do
     officer_assignment_2 = create(:poll_officer_assignment, booth_assignment: booth_assignment, officer: officer2)
 
     in_browser(:one) do
-      login_as user1
+      login_as officer1.user
       visit officing_root_path
     end
 
     in_browser(:two) do
-      login_as user2
+      login_as officer2.user
       visit officing_root_path
     end