Description of problem:
virt-install man page typo issue for "--launchSecurity" option

Version-Release number of selected component (if applicable):
kernel-4.18.0-128.el8.x86_64
virt-manager-2.2.1-1.el8.noarch
libvirt-4.5.0-31.module+el8.1.0+3808+3325c1a3.x86_64
qemu-kvm-2.12.0-83.module+el8.1.0+3852+0ba8aef0.x86_64
python3-libvirt-4.5.0-2.module+el8.1.0+3531+2918145b.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Document checking for sev in virt-install man page

# man virt-install

------------------------------------------------------------------------------
Part-1 

       --launch-security TYPE[,OPTS]
           Enable launch security for the guest, e.g. AMD SEV.

           Use --launch-security=? to see a list of all available sub options. Complete details at <https://libvirt.org/formatdomain.html#launchSecurity>. Example invocations:

===Testing result: No option "--launch-security", it should be "--launchSecurity"

# virt-install --launch-security=? 
usage: virt-install --name NAME --memory MB STORAGE INSTALL [options]
virt-install: error: unrecognized arguments: --launch-security=?

# virt-install --launchSecurity=?
--launchSecurity options:
  clearxml
  cbitpos
  dhCert
  policy
  reducedPhysBits
  session
  type

------------------------------------------------------------------------------
Part-2

       Start an SEV launch security VM with 4GB RAM, 4GB+256MiB of hard_limit, with a couple of virtio devices:

       Note: The IOMMU flag needs to be turned on with driver.iommu for virtio devices. Usage of --memtune is currently required because of SEV limitations, refer to libvirt docs for a detailed
       explanation.

         # virt-install \
              --name foo \
              --memory 4096 \
              --boot uefi \
              --machine q35 \
              --memtune hard_limit=4563402 \
              --disk size=15,target.bus=scsi \
              --import \
              --controller type=scsi,model=virtio-scsi,driver.iommu=on \
              --controller type=virtio-serial,driver.iommu=on \
              --network network=default,model=virtio,driver.iommu=on \
              --rng driver,iommu=on \
              --memballoon driver.iommu=on \
              --launchSecurity sev

===Testing result: A typo issue found in "EXAMPLES", it should use '.' instead of ',' in string "--rng driver,iommu=on ". 
What's more, we cannot use it like this, we need specify rng type in command, such as "--rng type=/dev/random,driver.iommu=on "

Actual results:
As description.

Expected results:
Fix it.

Additional info:
https://bugzilla.redhat.com/show_bug.cgi?id=1501608#c22

V2 posted upstream: https://www.redhat.com/archives/virt-tools-list/2019-August/msg00023.html