Narrow the scope of a local variable.

This is better style and more symmetrical with the other if-branch.
This likely should have been included in 9de77b54 (which created
the opportunity), but it was overlooked.

Japin Li

Discussion: https://postgr.es/m/MEYP282MB16699FA4A7CD57EB250E871FB6A40@MEYP282MB1669.AUSP282.PROD.OUTLOOK.COM

src/backend/replication/logical/proto.c

@@ -493,7 +493,6 @@ logicalrep_write_tuple(StringInfo out, Relation rel, HeapTuple tuple, bool binar
 		HeapTuple	typtup;
 		Form_pg_type typclass;
 		Form_pg_attribute att = TupleDescAttr(desc, i);
-		char	   *outputstr;
 
 		if (att->attisdropped || att->attgenerated)
 			continue;
@@ -537,6 +536,8 @@ logicalrep_write_tuple(StringInfo out, Relation rel, HeapTuple tuple, bool binar
 		}
 		else
 		{
+			char	   *outputstr;
+
 			pq_sendbyte(out, LOGICALREP_COLUMN_TEXT);
 			outputstr = OidOutputFunctionCall(typclass->typoutput, values[i]);
 			pq_sendcountedtext(out, outputstr, strlen(outputstr), false);