hv: bugfix for sbuf reset

The sbuf is allocated for each pcpu by hypercall from SOS. Before launch
Guest OS, the script will offline cpus, which will trigger vcpu reset and
then reset sbuf pointer. But sbuf only initiate once by SOS, so these
cpus for Guest OS has no sbuf to use. Thus, when run 'acrntrace' on SOS,
there is no trace data for Guest OS.
To fix the issue, only reset the sbuf for SOS.

Tracked-On: #3335
Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Reviewed-by: Eddie Dong <eddie.dong@intel.com>
Reviewed-by: Yan, Like <like.yan@intel.com>

hypervisor/release/sbuf.c

@@ -4,6 +4,4 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#include <types.h>
-
-void sbuf_reset(__unused uint16_t pcpu_id) {}
+void sbuf_reset(void) {}