Add a comment for switch fallthrough to quiet lint warning

Some code has switch fallthrough cases, it causes some warning during
compiling. Adding a comment can quiet it.

Tracked-On:#1260
Signed-off-by: Chaohong Guo <chaohong.guo@intel.com>
Acked-by: Gen Zheng <gen.zheng@intel.com>

Author: chaohong-guo

hypervisor/debug/npk_log.c

@@ -44,6 +44,7 @@ void npk_log_setup(struct hv_npk_log_param *param)
 	case HV_NPK_LOG_CMD_CONF:
 		if (param->mmio_addr || param->loglevel != 0xffffU)
 			param->res = HV_NPK_LOG_RES_OK;
+		/* falls through */
 	case HV_NPK_LOG_CMD_ENABLE:
 		if (param->mmio_addr)
 			base = param->mmio_addr;

hypervisor/debug/shell.c

@@ -831,8 +831,10 @@ static int shell_loglevel(int argc, char **argv)
 	switch (argc) {
 	case 4:
 		npk_loglevel = atoi(argv[3]);
+		/* falls through */
 	case 3:
 		mem_loglevel = atoi(argv[2]);
+		/* falls through */
 	case 2:
 		console_loglevel = atoi(argv[1]);
 		break;