allow logdirty commands while paused (unbreaks 60dbe1+8f09f4)

allow logdirty commands while paused (unbreaks 60dbe1+8f09f4)

60dbe1+8f09f4 breaks HVM live migration: 60dbe1 causes xc_save to
attempt to disable logdirty mode while qemu is paused. 8f09f4 disables
most commands, including logdirty, while the domain is paused. So
xc_save times out waiting for qemu to respond to the logdirty disable
command, and live migration fails. Logdirty commands issued while
paused should not affect the stability of ioemu.

Signed-off-by: Brendan Cully <brendan@cs.ubc.ca>