selinux: Use fd_path instead of /dev/tap* to get context
selinux: Use fd_path instead of /dev/tap* to get context

/dev/tap* is an invalid path but it works with lax policy.
Make it work with more accurate policy as well

Reviewed-by: Daniel P. Berrangé <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>
Signed-off-by: Dominick Grift <2abdb4d04bf3f7fa0abfd70dd782bba1774a9329@gmail.com>

libvirt/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,zippy2/libvirt,libvirt/libvirt,olafhering/libvirt,nertpinx/libvirt,olafhering/libvirt,jfehlig/libvirt,nertpinx/libvirt,olafhering/libvirt,crobinso/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,olafhering/libvirt,jardasgit/libvirt,crobinso/libvirt,nertpinx/libvirt,libvirt/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,zippy2/libvirt,libvirt/libvirt,nertpinx/libvirt,jardasgit/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,jfehlig/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,crobinso/libvirt,zippy2/libvirt,zippy2/libvirt,crobinso/libvirt