Add missing newline.

Noticed while analyzing output code.

Bug: N/A
Test: visual inspection
Change-Id: I2a6b8ad44275f475c973404dba6b0cec86beaf7c
diff --git a/Interface.cpp b/Interface.cpp
index 073e44c..fef3a3d 100644
--- a/Interface.cpp
+++ b/Interface.cpp
@@ -273,7 +273,7 @@
                 }
             });
             out << ");\n";
-            out << "return ::android::hardware::Void();";
+            out << "return ::android::hardware::Void();\n";
         } } }, /* cppImpl */
         { { IMPL_INTERFACE, [this](auto &out) {
             std::vector<const Interface *> chain = typeChain();