PerformScan: Rename fromLastJson in pruneRecordExposes()

The initial code motion preserved the name to minimise the differences.
Rename the variable now so it's a little more sensible.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: I54ce197e25d280e6a1fd5ee5c6d74bdce974bea1
diff --git a/src/PerformScan.cpp b/src/PerformScan.cpp
index e26ca5e..a3c240a 100644
--- a/src/PerformScan.cpp
+++ b/src/PerformScan.cpp
@@ -244,10 +244,10 @@
     _callback(std::move(callback))
 {}
 
-static void pruneRecordExposes(nlohmann::json& fromLastJson)
+static void pruneRecordExposes(nlohmann::json& record)
 {
-    auto findExposes = fromLastJson.find("Exposes");
-    if (findExposes != fromLastJson.end())
+    auto findExposes = record.find("Exposes");
+    if (findExposes != record.end())
     {
         auto copy = nlohmann::json::array();
         for (auto& expose : *findExposes)