lxd/network/network/utils/sriov: Remove use of lock from SRIOVFindFreeVirtualFunction
lxd/network/network/utils/sriov: Remove use of lock from SRIOVFindFreeVirtualFunction

The lock needs to be taken before calling SRIOVFindFreeVirtualFunction so the claim step can be locked as well.

Signed-off-by: Thomas Parrott <6b778ce645fb0e3dde76d79eccad490955b1ae74@canonical.com>

lxc/lxd,hallyn/lxd,stgraber/lxd,lxc/lxd,hallyn/lxd,stgraber/lxd,lxc/lxd,lxc/lxd,lxc/lxd,lxc/lxd,lxc/lxd,stgraber/lxd,hallyn/lxd,hallyn/lxd,stgraber/lxd,hallyn/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,stgraber/lxd