improve comments on CreateFunction returnsSet

[Zshengbin91]

Hi hackers,

I'm using postgres, and I found a potentially ambiguous code comment in the
`CreateFunction` function. `returnsSet` is a boolean variable, and to be
consistent with the subsequent error message, I believe the comment should
be modified to match the error message. "reject ROWS if it's not
returnsSet" should be changed to "reject ROWS if it does not return a set"
 Therefore, I've attached a patch to address this issue.

Thanks!
Br/Shengbin Zhao

diff --git a/src/backend/commands/functioncmds.c 
b/src/backend/commands/functioncmds.c
old mode 100644
new mode 100755
index 8a435cd93db..01d21098e06
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -1245,7 +1245,7 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt 
*stmt)
 
        /*
         * Set default values for COST and ROWS depending on other parameters;
-        * reject ROWS if it's not returnsSet.  NB: pg_dump knows these default
+        * reject ROWS if it does not return a set.  NB: pg_dump knows these 
default
         * values, keep it in sync if you change them.
         */
        if (procost < 0)