maint: use consistent if-else braces in conf and friends

maint: use consistent if-else braces in conf and friends

I'm about to add a syntax check that enforces our documented
HACKING style of always using matching {} on if-else statements.

This patch focuses on code shared between multiple drivers.

* src/conf/domain_conf.c (virDomainFSDefParseXML)
(virSysinfoParseXML, virDomainNetDefParseXML)
(virDomainWatchdogDefParseXML)
(virDomainRedirFilterUSBDevDefParseXML): Correct use of {}.
* src/conf/interface_conf.c (virInterfaceDefParseDhcp)
(virInterfaceDefParseIp, virInterfaceVlanDefFormat)
(virInterfaceDefParseStartMode, virInterfaceDefParseBondMode)
(virInterfaceDefParseBondMiiCarrier)
(virInterfaceDefParseBondArpValid): Likewise.
* src/conf/node_device_conf.c (virNodeDevCapStorageParseXML):
Likewise.
* src/conf/nwfilter_conf.c (virNWFilterRuleDetailsParse)
(virNWFilterRuleParse, virNWFilterDefParseXML): Likewise.
* src/conf/secret_conf.c (secretXMLParseNode): Likewise.
* src/cpu/cpu_x86.c (x86Baseline, x86FeatureLoad, x86ModelLoad):
Likewise.
* src/network/bridge_driver.c (networkKillDaemon)
(networkDnsmasqConfContents): Likewise.
* src/node_device/node_device_hal.c (dev_refresh): Likewise.
* src/nwfilter/nwfilter_gentech_driver.c (virNWFilterInstantiate):
Likewise.
* src/nwfilter/nwfilter_ebiptables_driver.c
(_iptablesCreateRuleInstance): Likewise.
* src/storage/storage_backend_disk.c
(virStorageBackendDiskBuildPool): Likewise.

Signed-off-by: Eric Blake <eblake@redhat.com>