Remove a redundant test for multiple output columns in a scalar subquery.

FossilOrigin-Name: 657472bce2b2fe6f3d4bbead5301f658812b937d

src/select.c

@@ -491,11 +491,13 @@ static void codeDistinct(
   sqlite3ReleaseTempReg(pParse, r1);
 }
 
+#ifndef SQLITE_OMIT_SUBQUERY
 /*
 ** Generate an error message when a SELECT is used within a subexpression
 ** (example:  "a IN (SELECT * FROM table)") but it has more than 1 result
-** column.  We do this in a subroutine because the error occurs in multiple
-** places.
+** column.  We do this in a subroutine because the error used to occur
+** in multiple places.  (The error only occurs in one place now, but we
+** retain the subroutine to minimize code disruption.)
 */
 static int checkForMultiColumnSelectError(
   Parse *pParse,       /* Parse context. */
@@ -511,6 +513,7 @@ static int checkForMultiColumnSelectError(
     return 0;
   }
 }
+#endif
 
 /*
 ** This routine generates the code for the inside of the inner loop
@@ -590,10 +593,6 @@ static void selectInnerLoop(
     }
   }
 
-  if( checkForMultiColumnSelectError(pParse, pDest, pEList->nExpr) ){
-    return;
-  }
-
   switch( eDest ){
     /* In this mode, write each query result to the key of the temporary
     ** table iParm.