[Fix] no-is-mounted: fix logic in method name check

The last change to `no-is-mounted` caused the rule to error
with any method name, not just with "isMounted".

Author: Mathias-S

Diff for: lib/rules/no-is-mounted.js

@@ -41,7 +41,8 @@ module.exports = {
         }
         if (
           callee.object.type !== 'ThisExpression'
-          && (!('name' in callee.property) || callee.property.name !== 'isMounted')
+          || !('name' in callee.property)
+          || callee.property.name !== 'isMounted'
         ) {
           return;
         }

Diff for: tests/lib/rules/no-is-mounted.js

@@ -57,6 +57,17 @@ ruleTester.run('no-is-mounted', rule, {
         });
       `,
     },
+    {
+      code: `
+        class Hello extends React.Component {
+          notIsMounted() {}
+          render() {
+            this.notIsMounted();
+            return <div>Hello</div>;
+          }
+        };
+      `,
+    },
   ]),
 
   invalid: parsers.all([