read_fru_data: use structured bindings in fru loop

Use structured bindings for first/second in fru loop.

Change-Id: Ief5460946ead910ccae653ebb6f9d894805b756d
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/read_fru_data.cpp b/read_fru_data.cpp
index 4723308..44ea11c 100644
--- a/read_fru_data.cpp
+++ b/read_fru_data.cpp
@@ -81,18 +81,14 @@
     {
         path.erase(0, strlen(OBJ_PATH));
     }
-    for (auto& fru : frus)
+    for (const auto& [fruId, instanceList] : frus)
     {
-        auto& instanceList = fru.second;
-
         auto found = std::find_if(
             instanceList.begin(), instanceList.end(),
             [&path](const auto& iter) { return (iter.path == path); });
 
         if (found != instanceList.end())
         {
-            auto& fruId = fru.first;
-
             cache::fruMap.erase(fruId);
             break;
         }