Fixed typo, added more tests

Author: sergei-startsev

lib/util/Components.js

@@ -501,7 +501,7 @@ function componentRule(rule, context) {
       scope = scope.upper;
       while (scope) {
         const type = scope.block.type;
-        if (type === 'FunctionExpression' || type === 'FunctionExpression') {
+        if (type === 'FunctionExpression' || type === 'FunctionDeclaration') {
           return scope;
         }
         scope = scope.upper;

tests/lib/rules/no-this-in-sfc.js

@@ -185,5 +185,12 @@ ruleTester.run('no-this-in-sfc', rule, {
       return <div onClick={onClick}>{this.props.foo}</div>;
     }`,
     errors: [{message: ERROR_MESSAGE}, {message: ERROR_MESSAGE}]
+  }, {
+    code: `
+    () => {
+      this.something();
+      return null;
+    }`,
+    errors: [{message: ERROR_MESSAGE}]
   }]
 });