Refactor some internal object element names used by the busy handler, to
simplify analysis.

FossilOrigin-Name: 6c40c5574f4ae9795a142d01a8f84afd1b72678ea5f6bfca14a8646c4e862605
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 216a500..b10fe94 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -961,9 +961,9 @@
 */
 typedef struct BusyHandler BusyHandler;
 struct BusyHandler {
-  int (*xFunc)(void *,int);  /* The busy callback */
-  void *pArg;                /* First arg to busy callback */
-  int nBusy;                 /* Incremented with each busy call */
+  int (*xBusyHandler)(void *,int);  /* The busy callback */
+  void *pBusyArg;                   /* First arg to busy callback */
+  int nBusy;                        /* Incremented with each busy call */
 };
 
 /*