comment fixes

hi,

see the following patch.
it seems some function names in the comment are out of sync with the reality.

YAMAMOTO Takashi

diff --git a/src/backend/executor/execProcnode.c b/src/backend/executor/execProcnode.c
index 8bdfad2..284fc6a 100644
--- a/src/backend/executor/execProcnode.c
+++ b/src/backend/executor/execProcnode.c
@@ -55,7 +55,7 @@
* of ExecInitNode() is a plan state tree built with the same structure
* as the underlying plan tree.
*
- * * Then when ExecRun() is called, it calls ExecutePlan() which calls
+ * * Then when ExecutorRun() is called, it calls ExecutePlan() which calls
* ExecProcNode() repeatedly on the top node of the plan state tree.
* Each time this happens, ExecProcNode() will end up calling
* ExecNestLoop(), which calls ExecProcNode() on its subplans.
@@ -65,7 +65,7 @@
* form the tuples it returns.
*
* * Eventually ExecSeqScan() stops returning tuples and the nest
- * loop join ends. Lastly, ExecEnd() calls ExecEndNode() which
+ * loop join ends. Lastly, ExecutorEnd() calls ExecEndNode() which
* calls ExecEndNestLoop() which in turn calls ExecEndNode() on
* its subplans which result in ExecEndSeqScan().
*