qemu_monitor_json: Drop pointless error labels
qemu_monitor_json: Drop pointless error labels

After previous cleanups, some 'error' labels were rendered
needless - they contain nothing more than a return statement.
Well, those labels can be dropped and 'goto error' can be
replaced with return statement directly.

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

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