qcacmn: wmi: Replace fallthrough comment with attribute

-Wimplicit-fallthrough is being enabled by default. Some compilers
such as clang require the attribute instead of just a fallthrough comment.

Change-Id: If7b79684df22441de75447dda84d22576573bfc5
CRs-Fixed: 3218242

wmi/src/wmi_unified_11be_tlv.c

@@ -418,7 +418,7 @@ send_mlo_link_set_active_cmd_tlv(wmi_unified_t wmi_handle,
 	case WMI_MLO_LINK_FORCE_ACTIVE_LINK_NUM:
 	case WMI_MLO_LINK_FORCE_INACTIVE_LINK_NUM:
 		num_link_num_param = param->num_link_entry;
-		/* fallthrough */
+		fallthrough;
 	case WMI_MLO_LINK_FORCE_ACTIVE:
 	case WMI_MLO_LINK_FORCE_INACTIVE:
 	case WMI_MLO_LINK_NO_FORCE: