snapshot: simplify indentation of network xml

snapshot: simplify indentation of network xml

More simplifications possible due to auto-indent.  Also,
<bandwidth> within <actual> was only using 6 instead of 8 spaces.

* src/util/network.h (virVirtualPortProfileFormat)
(virBandwidthDefFormat): Alter signature.
* src/util/network.c (virVirtualPortProfileFormat)
(virBandwidthDefFormat): Alter indentation.
(virBandwidthChildDefFormat): Tweak to make use easier.
* src/conf/network_conf.c (virPortGroupDefFormat)
(virNetworkDefFormat): Adjust callers.
* src/conf/domain_conf.c (virDomainNetDefFormat): Likewise.
(virDomainActualNetDefFormat): Likewise, and fix bandwidth
indentation.