Remove dependency on Note instance from notes edit form.

app/views/projects/notes/_edit_form.html.haml

 .note-edit-form
-  = form_for note, url: namespace_project_note_path(@project.namespace, @project, note), method: :put, remote: true, authenticity_token: true, html: { class: 'edit-note common-note-form js-quick-submit' } do |f|
-    = note_target_fields(note)
+  = form_tag '#', method: :put, remote: true, class: 'edit-note common-note-form js-quick-submit' do
     = render layout: 'projects/md_preview', locals: { preview_class: 'md-preview' } do
-      = render 'projects/zen', f: f, attr: :note, classes: 'note-textarea js-note-text js-task-list-field', placeholder: "Write a comment or drag your files here..."
+      = render 'projects/zen', attr: 'note[note]', classes: 'note-textarea js-note-text js-task-list-field', placeholder: "Write a comment or drag your files here..."
       = render 'projects/notes/hints'
 
     .note-form-actions.clearfix
-      = f.submit 'Save Comment', class: 'btn btn-nr btn-save js-comment-button'
+      = submit_tag 'Save Comment', class: 'btn btn-nr btn-save js-comment-button'
       %span.settings-message.note-edit-warning.js-edit-warning
         Finish editing this message first!
       %button.btn.btn-nr.btn-cancel.note-edit-cancel{ type: 'button' }

app/views/projects/notes/_notes.html.haml

@@ -7,5 +7,4 @@
 - else
   = render partial: "projects/notes/note", collection: @notes, as: :note
 
-= render 'projects/notes/edit_form', note: @notes[0]
-= hidden_field_tag :authenticity_token, form_authenticity_token
+= render 'projects/notes/edit_form'