qemu_monitor_json: Don't check for qemuMonitorNextCommandID() retval
qemu_monitor_json: Don't check for qemuMonitorNextCommandID() retval

The qemuMonitorNextCommandID() function can never fail. There's
no need to check for its retval then. Moreover, the temporary
variable used to hold the retval can be declared in the inner
most block.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: Tim Wiederhake <da93ee425e056cfcf1ddac9fc87851b25464abf4@redhat.com>

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