Fix output file path when package is not set

It's been "out//Foo.java" when the package is not set.
Now, it's fixed to return "out/Foo.java".

Bug: none
Test: aidl_unittests/ aidl_integration_test
Change-Id: Id175e369d591932fe1ce87f1c7e641d8dfa3cfa4
diff --git a/options.cpp b/options.cpp
index 74de18f..58aea82 100644
--- a/options.cpp
+++ b/options.cpp
@@ -387,7 +387,7 @@
         // when output is omitted and -o option isn't set, the output is by
         // default set to the input file path with .aidl is replaced to .java.
         // If -o option is set, the output path is calculated by
-        // generate_outputFileName which returns "<output_dir>/<package/name>/
+        // GetOutputFilePath which returns "<output_dir>/<package/name>/
         // <typename>.java"
         output_file_ = input_files_.front();
         if (android::base::EndsWith(output_file_, ".aidl")) {