Convert FoldInitializerAndIfToElvisIntention to inspection and decrease severity to INFO

#KT-19643 Fixed

idea/testData/inspectionsLocal/foldInitializerAndIfToElvis/Comments2.kt

@@ -0,0 +1,8 @@
+fun foo(p: List<String?>): Int {
+    val v = p[0]
+    <caret>if (v == null) { // v is null
+        // we should do something with it
+        return -1 // let's return -1
+    } // end of if
+    return v.length
+}