[IA64] Fix xm pause/unpause bug

[IA64] Fix xm pause/unpause bug

This small patch intends to fix domain pause/unpause bug.
Current xm pause operation will do sync_vcpu_execstate to
sync vcpu status, but it saves dom0's fpu and other registers
to VTi domain or domainU due to xm pause from control panel.
Because sync_vcpu_execstate was called after vcpu_sleep which
has saved all status when schedule out ,in addition, currently
no lazy states need to be saved in IPF side, so sync_vcpu_execstate
would need do nothing now.

Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Zhang xiantao <xiantao.zhang@intel.com>