During text mode installation, No input is accepted to cancel the "Detecting the link on eth0" after an network configuration

Bug originally reported by Manvanthara Puttashankar

Host details:
Platform: PPC64LE
[root@localhost ~]# uname -a
Linux localhost 3.10.23-900.pkvm2_1.1.ppc64 #1 SMP Wed Feb 5 02:46:25 CST 2014 ppc64 ppc64 ppc64 GNU/Linux
[root@localhost ~]# cat /etc/issue
IBM PowerKVM release 2.1 build 9 Beta (pkvm2_1)
Kernel \r on a \m (\l)

Ubuntu details:
Daily Build: Ubuntu 14.04 Alpha2 feb28

Summary: During text mode installation, No input is accepted to cancel the "Detecting the link on eth0" after an network configuration.

Steps to reproduce:
1. [root@localhost manu]# qemu-img create -f qcow2 ubuntu_alpha3_M1.qcow2 80G
Formatting 'ubuntu_alpha3_M1.qcow2', fmt=qcow2 size=85899345920 encryption=off cluster_size=65536 lazy_refcounts=off

2.[root@localhost manu]# virt-install --name=manu1_alpha3 --ram 2048 --cdrom /var/lib/libvirt/images/Alpha_ISO/trusty-server-ppc64el.iso --disk path=/var/lib/libvirt/images/manu/ubuntu_alpha3_M1.qcow2,bus=virtio,size=10,format=qcow2,cache=none --bridge=virbr0 --mac=52:54:02:70:75:6C

3. During the installation, configure the network manually

4. Once the network inputs are accepted, The installer proceeds to "Detecting the link on eth0; please wait"

5. here if the user decides to interrupt it, the installer doesn't accept any inputs like space, enter etc.
   installer exits only after its timeout value.

Expected Behavior: Since there is an option <cancel> provided, the inputs (like space or enter )needs to be accepted.

If you are using expert option, The installer asks if the automatic configure using DHCP is required you could select no and enter the manual network configuration.

Else if you are using install option, If your DHCP configuration fails it enters manual configuration.

You could use either of the methods to recreate the issue.