KT-38841 Remove redundant preparePsiElementForWrite call

- This call breaks Intention Preview for all intentions that extend
`SelfTargetingIntention`
- This check is actually already performed by the platform before the
intention invocation
- There are many other intentions which redundantly use this call, but
most of them implement `LocalQuickFix`, which means that they are
inspection based. Currently Intention Preview does not seem to support
this kind of intentions

idea/idea-analysis/src/org/jetbrains/kotlin/idea/intentions/SelfTargetingIntention.kt

@@ -99,7 +99,6 @@ abstract class SelfTargetingIntention<TElement : PsiElement>(
     final override fun invoke(project: Project, editor: Editor?, file: PsiFile) {
         editor ?: return
         val target = getTarget(editor, file) ?: return
-        if (!FileModificationService.getInstance().preparePsiElementForWrite(target)) return
         applyTo(target, editor)
     }