Bug 960960

Description
No error messages show when the console type in xml is different with guest

Version:
libvirt-1.0.3-1.el7.x86_64(As there is bug 927176 block migration,so I use old libvirt and qemu-kvm version)
qemu-kvm-1.3.0-6.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1.Prepare guest migration environment.
2.Install a guest and dumpxml for guest on one host.
# virsh dumpxml mig > test-console.xml
It's console part is as below:
    <console type='pty' tty='/dev/pts/3'>
      <source path='/dev/pts/3'/>
      <target type='serial' port='0'/>
      <alias name='serial0'/>
    </console>


3.Change console type in test-console.xml,eg:change 
    <console type='pty' tty='/dev/pts/3'>
      <source path='/dev/pts/3'/>
      <target type='serial' port='0'/>
      <alias name='serial0'/>
    </console>
to:
    <console type='stdio' tty='/dev/pts/3'>
      <source path='/dev/pts/3'/>
      <target type='serial' port='0'/>
      <alias name='serial0'/>
    </console>


4.Do migration using test-console.xml,no error messages show and it can migrate successfully
# virsh migrate --live --xml mig-test.xml mig-test qemu+ssh://10.66.7.153/system
root.7.153's password: 

Actual results：
As describes.
No error messages show and it can migrate successfully

Expected results:
Something like:
error:Target console type stdio does not match source pty

Additional info:
After migration,the console type on target machine is "pty".