maint: use consistent if-else braces in qemu

maint: use consistent if-else braces in qemu

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

This commit focuses on the qemu driver.

* src/qemu/qemu_command.c (qemuParseISCSIString)
(qemuParseCommandLineDisk, qemuParseCommandLine)
(qemuBuildSmpArgStr, qemuBuildCommandLine)
(qemuParseCommandLineDisk, qemuParseCommandLineSmp): Correct use
of {}.
* src/qemu/qemu_capabilities.c (virQEMUCapsProbeCPUModels):
Likewise.
* src/qemu/qemu_driver.c (qemuDomainCoreDumpWithFormat)
(qemuDomainRestoreFlags, qemuDomainGetInfo)
(qemuDomainMergeBlkioDevice): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainAttachNetDevice): Likewise.
* src/qemu/qemu_monitor_text.c (qemuMonitorTextCreateSnapshot)
(qemuMonitorTextLoadSnapshot, qemuMonitorTextDeleteSnapshot):
Likewise.
* src/qemu/qemu_process.c (qemuProcessStop): Likewise.

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