Change expected format for text differences

In Stack this is presented as HTML which needs to have normalized escaping
rules. In Fiber it is currently not presented as HTML but a raw string
so we don't escape it.

scripts/fiber/tests-passing-except-dev.txt

@@ -10,4 +10,3 @@ src/renderers/dom/shared/__tests__/ReactDOMServerIntegration-test.js
 
 src/renderers/dom/shared/__tests__/ReactMount-test.js
 * should warn if mounting into dirty rendered markup
-* should account for escaping on a checksum mismatch

scripts/fiber/tests-passing.txt

@@ -1567,6 +1567,7 @@ src/renderers/dom/shared/__tests__/ReactMount-test.js
 * should reuse markup if rendering to the same target twice
 * should not warn if mounting into non-empty node
 * should warn when mounting into document.body
+* should account for escaping on a checksum mismatch
 * should warn if render removes React-rendered children
 * should warn if the unmounted node was rendered by another copy of React
 * passes the correct callback context

src/renderers/dom/shared/__tests__/ReactMount-test.js

@@ -194,10 +194,17 @@ describe('ReactMount', () => {
       div,
     );
     expectDev(console.error.calls.count()).toBe(1);
-    expectDev(console.error.calls.argsFor(0)[0]).toContain(
-      ' (client) nbsp entity: &nbsp; client text</div>\n' +
-        ' (server) nbsp entity: &nbsp; server text</div>',
-    );
+    if (ReactDOMFeatureFlags.useFiber) {
+      expectDev(console.error.calls.argsFor(0)[0]).toContain(
+        'Server: "This markup contains an nbsp entity:   server text" ' +
+          'Client: "This markup contains an nbsp entity:   client text"',
+      );
+    } else {
+      expectDev(console.error.calls.argsFor(0)[0]).toContain(
+        ' (client) nbsp entity: &nbsp; client text</div>\n' +
+          ' (server) nbsp entity: &nbsp; server text</div>',
+      );
+    }
   });
 
   if (WebComponents !== undefined) {