Remove unnecessary std::move

Moving a temporary object prevents copy elision, and could reduce
performance.

This fixes -Wpessimizing-move compiler warning.

Test: presubmit
Bug: 154270751
Change-Id: Ia0b02d90c239572c953007272f75900ee77c6305
diff --git a/services/camera/libcameraservice/api1/Camera2Client.cpp b/services/camera/libcameraservice/api1/Camera2Client.cpp
index caa6424..6347863 100644
--- a/services/camera/libcameraservice/api1/Camera2Client.cpp
+++ b/services/camera/libcameraservice/api1/Camera2Client.cpp
@@ -419,7 +419,7 @@
         result << "    none\n";
     }
 
-    std::string resultStr = std::move(result.str());
+    std::string resultStr = result.str();
 
     write(fd, resultStr.c_str(), resultStr.size());