[troubleshooting] Remove QEMU workaround.

The bug mentioned was resolved years ago in EL 7.2.

Change-Id: Iac543b04a627993491ef1a1abbf112516a8823fe
Signed-off-by: Luke Short <ekultails@gmail.com>

deploy-guide/source/troubleshooting/index.rst

@@ -12,4 +12,3 @@ This section contains troubleshooting related topics for |project|.
    troubleshooting-nodes
    troubleshooting-overcloud
    troubleshooting-tripleo-heat-templates
-   troubleshooting-virt-setup

deploy-guide/source/troubleshooting/troubleshooting-virt-setup.rst

@@ -1,25 +0,0 @@
-Troubleshooting instack-virt-setup Failures
--------------------------------------------
-
-Known Issues:
-^^^^^^^^^^^^^
-
-* Due to a `bug in libvirt`_, it is possible for instack-virt-setup to fail
-  with an error such as the following::
-
-      libvirt: QEMU Driver error : unsupported configuration: This QEMU doesn't support virtio scsi controller
-      Traceback (most recent call last):
-      File "/usr/libexec/openstack-tripleo/configure-vm", line 133, in <module>
-          main()
-      File "/usr/libexec/openstack-tripleo/configure-vm", line 129, in main
-          a = conn.defineXML(libvirt_template)
-      File "/usr/lib64/python2.7/site-packages/libvirt.py", line 3445, in defineXML
-          if ret is None:raise libvirtError('virDomainDefineXML() failed', conn=self)
-      libvirt.libvirtError: unsupported configuration: This QEMU doesn't support virtio scsi controller
-
-  The workaround is to do delete the libvirt capabilities cache and restart the service::
-
-      $ rm -Rf  /var/cache/libvirt/qemu/capabilities/
-      $ systemctl restart libvirtd
-
-.. _bug in libvirt: https://bugzilla.redhat.com/show_bug.cgi?id=1195882

deploy-guide/source/troubleshooting/troubleshooting.rst

@@ -7,7 +7,6 @@ help with troubleshooting when using |project|.
 .. toctree::
    :maxdepth: 2
 
-   troubleshooting-virt-setup
    troubleshooting-image-build
    troubleshooting-nodes
    troubleshooting-overcloud