HV:common:fix "expression is not Boolean"

MISRA C explicit required expression should be boolean when
in branch statements (if,while...).

Signed-off-by: Huihuang Shi <huihuang.shi@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

hypervisor/common/stack_protector.c

@@ -8,5 +8,5 @@
 
 void __stack_chk_fail(void)
 {
-	ASSERT(0, "stack check fails in HV\n");
+	ASSERT(false, "stack check fails in HV\n");
 }