init: fix clang-tidy performance issues

Test: boot, init unit tests
Change-Id: Iccf34d2fedfa543dd9f29e010cbb6d8fe9cf5983
diff --git a/init/parser.cpp b/init/parser.cpp
index bbfbdc6..6ab61cb 100644
--- a/init/parser.cpp
+++ b/init/parser.cpp
@@ -37,7 +37,7 @@
 }
 
 void Parser::AddSingleLineParser(const std::string& prefix, LineCallback callback) {
-    line_callbacks_.emplace_back(prefix, callback);
+    line_callbacks_.emplace_back(prefix, std::move(callback));
 }
 
 void Parser::ParseData(const std::string& filename, std::string* data) {