x86/hyper-v: Fix indentation in hv_do_fast_hypercall16()

Remove the surplus TAB in hv_do_fast_hypercall16().
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: kys@microsoft.com
Cc: haiyangz@microsoft.com
Cc: sthemmin@microsoft.com
Cc: bp@alien8.de
Cc: hpa@zytor.com
Cc: devel@linuxdriverproject.org
Cc: zhong.weidong@zte.com.cn
Link: https://lkml.kernel.org/r/1540797451-2792-1-git-send-email-wang.yi59@zte.com.cn