Fix typo in description of ExecFindPartition

Author: Amit Langote
Discussion: https://postgr.es/m/CA+HiwqHg0=UL+Dhh3gpiwYNA=ufk9Lb7GQ2c=5rs=ZmVTP7xAw@mail.gmail.com

Author: michaelpq

src/backend/executor/execPartition.c

@@ -259,8 +259,8 @@ ExecSetupPartitionTupleRouting(ModifyTableState *mtstate, Relation rel)
  * scratch space.
  *
  * If no leaf partition is found, this routine errors out with the appropriate
- * error message.  An error may also raised if the found target partition is
- * not a valid target for an INSERT.
+ * error message.  An error may also be raised if the found target partition
+ * is not a valid target for an INSERT.
  */
 ResultRelInfo *
 ExecFindPartition(ModifyTableState *mtstate,