Hardcode backlinks

app/views/merge_requests/absorbing_organisation.html.erb

@@ -1,7 +1,7 @@
 <% content_for :before_content do %>
   <% title = "Tell us if your organisation is merging" %>
   <% content_for :title, title %>
-  <%= govuk_back_link(href: :back) %>
+  <%= govuk_back_link href: organisations_merge_request_path(id: @merge_request) %>
 <% end %>
 
 <h2 class="govuk-heading-l">Which organisation is absorbing the others?</h2>

app/views/merge_requests/confirm_telephone_number.html.erb

@@ -1,7 +1,7 @@
 <% content_for :before_content do %>
   <% title = "Tell us if your organisation is merging" %>
   <% content_for :title, title %>
-  <%= govuk_back_link(href: :back) %>
+  <%= govuk_back_link href: absorbing_organisation_merge_request_path(id: @merge_request) %>
 <% end %>
 
 <h2 class="govuk-heading-l">What is <%= @merge_request.absorbing_organisation.name %>'s telephone number?</h2>

app/views/merge_requests/new_org_name.html.erb

@@ -1,7 +1,7 @@
 <% content_for :before_content do %>
   <% title = "Tell us if your organisation is merging" %>
   <% content_for :title, title %>
-  <%= govuk_back_link(href: :back) %>
+  <%= govuk_back_link href: absorbing_organisation_merge_request_path(id: @merge_request) %>
 <% end %>
 
 Provide new org name