Fix an always-true conditional left over from the previous commit.

FossilOrigin-Name: ab12fce3318db447995e1465f34a1e43cd623d6a
diff --git a/src/expr.c b/src/expr.c
index 0640029..31128cc 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -3176,7 +3176,7 @@
   struct yColCache *p;
 
   for(i=0, p=pParse->aColCache; i<pParse->nColCache; i++, p++){
-    if( p->iReg>0 && p->iTable==iTable && p->iColumn==iColumn ){
+    if( p->iTable==iTable && p->iColumn==iColumn ){
       p->lru = pParse->iCacheCnt++;
       sqlite3ExprCachePinRegister(pParse, p->iReg);
       return p->iReg;