Unused variable `attrs_used` and redundant `pull_varattnos` call in `mysqlGetForeignRelSize`

[Meta11ic0]

Bug Report

Summary

In mysqlGetForeignRelSize() (mysql_fdw.c), a local variable attrs_used
is declared and populated via pull_varattnos(), but its result is never
read or used anywhere afterward. The same expression tree is collected again
a few lines later into fpinfo->attrs_used, which is the variable actually
consumed by the rest of the planning logic.

Redundant code

/* Line ~991 */
Bitmapset  *attrs_used = NULL;

/* Lines ~1026-1027: result written to attrs_used but never read */
pull_varattnos((Node *) baserel->reltarget->exprs, baserel->relid,
               &attrs_used);

[surajkharage19]

Thanks @Meta11ic0 for reporting the redundant code.

You are correct, We will fix this.