FQName tokenName respect empty mName.

This way,
ANDROID_HARDWARE_WIFI_OFFLOAD_V1_0__OFFLOAD_H
->
ANDROID_HARDWARE_WIFI_OFFLOAD_V1_0_OFFLOAD_H
for instance.

Test: hidl_test, manually verify output of -Lc++-impl
Change-Id: Ibc2f195d83541011c35437411fd7e673f26f7813
diff --git a/FQName.cpp b/FQName.cpp
index df0515c..908d39b 100644
--- a/FQName.cpp
+++ b/FQName.cpp
@@ -295,10 +295,12 @@
     std::vector<std::string> components;
     getPackageAndVersionComponents(&components, true /* cpp_compatible */);
 
-    std::vector<std::string> nameComponents;
-    StringHelper::SplitString(mName, '.', &nameComponents);
+    if (!mName.empty()) {
+        std::vector<std::string> nameComponents;
+        StringHelper::SplitString(mName, '.', &nameComponents);
 
-    components.insert(components.end(), nameComponents.begin(), nameComponents.end());
+        components.insert(components.end(), nameComponents.begin(), nameComponents.end());
+    }
 
     return StringHelper::JoinStrings(components, "_");
 }