qemuMonitorTextGetAllBlockStatsInfo: Fix line validation
qemuMonitorTextGetAllBlockStatsInfo: Fix line validation

There's a bug in the function. We expect the following format for
the data we are parsing here:

  key: value

So we use strchr() to find ':' and then see if it is followed by
space. But the check that does just that is slightly incorrect.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

andreabolognani/libvirt,fabianfreyer/libvirt,zippy2/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,eskultety/libvirt,crobinso/libvirt,eskultety/libvirt,nertpinx/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,eskultety/libvirt,taget/libvirt,nertpinx/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,datto/libvirt,taget/libvirt,olafhering/libvirt,jfehlig/libvirt,eskultety/libvirt,libvirt/libvirt,libvirt/libvirt,crobinso/libvirt,jfehlig/libvirt,taget/libvirt,nertpinx/libvirt,crobinso/libvirt,fabianfreyer/libvirt,taget/libvirt,VenkatDatta/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,eskultety/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,olafhering/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,andreabolognani/libvirt,zippy2/libvirt,datto/libvirt,datto/libvirt,andreabolognani/libvirt,zippy2/libvirt,datto/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,libvirt/libvirt,jardasgit/libvirt,olafhering/libvirt,taget/libvirt,crobinso/libvirt,jardasgit/libvirt,zippy2/libvirt,datto/libvirt,olafhering/libvirt,jfehlig/libvirt,libvirt/libvirt