Replace @user with current_user on Account page

Previously we used @user, but this changed to local_assigns[:user]
so we could pass a second variable to the view from an EE module

Since we were already using current_user librally there it makes sense
to replace the remaining usages.

See: https://docs.gitlab.com/ee/development/module_with_instance_variables.html

app/controllers/profiles/accounts_controller.rb

@@ -27,6 +27,6 @@ class Profiles::AccountsController < Profiles::ApplicationController
   private
 
   def show_view_variables
-    { user: current_user }
+    {}
   end
 end

app/views/profiles/accounts/show.html.haml

 - page_title "Account"
 - @content_class = "limit-container-width" unless fluid_layout
-- user = local_assigns.fetch(:user)
 
 - if current_user.ldap_user?
   .alert.alert-info
@@ -68,7 +67,7 @@
     %h4.prepend-top-0.danger-title
       = s_('Profiles|Delete account')
   .col-lg-8
-    - if user.can_be_removed? && can?(current_user, :destroy_user, user)
+    - if current_user.can_be_removed? && can?(current_user, :destroy_user, current_user)
       %p
         = s_('Profiles|Deleting an account has the following effects:')
       = render 'users/deletion_guidance', user: current_user
@@ -81,10 +80,10 @@
         confirm_with_password: ('true' if current_user.confirm_deletion_with_password?),
         username: current_user.username } }
     - else
-      - if user.solo_owned_groups.present?
+      - if current_user.solo_owned_groups.present?
         %p
           = s_('Profiles|Your account is currently an owner in these groups:')
-          %strong= user.solo_owned_groups.map(&:name).join(', ')
+          %strong= current_user.solo_owned_groups.map(&:name).join(', ')
         %p
           = s_('Profiles|You must transfer ownership or delete these groups before you can delete your account.')
       - else