Fix merge issue for promise-function-async (palantir#1792)

Author: nchen63

src/rules/promiseFunctionAsyncRule.ts

@@ -40,8 +40,8 @@ export class Rule extends Lint.Rules.TypedRule {
 
     public static FAILURE_STRING = "functions that return promises must be async";
 
-    public applyWithProgram(sourceFile: ts.SourceFile, program: ts.Program): Lint.RuleFailure[] {
-        return this.applyWithWalker(new PromiseAsyncWalker(sourceFile, this.getOptions(), program));
+    public applyWithProgram(sourceFile: ts.SourceFile, langSvc: ts.LanguageService): Lint.RuleFailure[] {
+        return this.applyWithWalker(new PromiseAsyncWalker(sourceFile, this.getOptions(), langSvc.getProgram()));
     }
 }