Fix PDO_Firebird tests which assume ERRMODE_SILENT

These have apparently been missed when PR 5388[1] had been merged.

[1] <#5388>

Author: cmb69

ext/pdo_firebird/tests/bug_47415.phpt

@@ -6,6 +6,7 @@ Bug #47415 PDO_Firebird segfaults when passing lowercased column name to bindCol
 <?php
 require 'testdb.inc';
 
+$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT);
 @$dbh->exec('DROP TABLE testz');
 $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);
 

ext/pdo_firebird/tests/bug_48877.phpt

@@ -9,6 +9,7 @@ require("testdb.inc");
 
 $value = '2';
 
+$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT);
 @$dbh->exec('DROP TABLE testz');
 $dbh->exec('CREATE TABLE testz (A integer)');
 $dbh->exec("INSERT INTO testz VALUES ('1')");

ext/pdo_firebird/tests/bug_53280.phpt

@@ -7,6 +7,7 @@ PDO_Firebird: bug 53280 segfaults if query column count is less than param count
 
 require("testdb.inc");
 
+$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT);
 @$dbh->exec('DROP TABLE testz');
 $dbh->exec('CREATE TABLE testz(A VARCHAR(30), B VARCHAR(30), C VARCHAR(30))');
 $dbh->exec("INSERT INTO testz VALUES ('A', 'B', 'C')");

ext/pdo_firebird/tests/rowCount.phpt

@@ -7,6 +7,7 @@ PDO_Firebird: rowCount
 
 require("testdb.inc");
 
+$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT);
 @$dbh->exec('DROP TABLE testz');
 $dbh->exec('CREATE TABLE testz (A VARCHAR(10))');
 $dbh->exec("INSERT INTO testz VALUES ('A')");