Merge pull request #2153 from ARMmbed/IOTTHD-3650

fhss_ws: typecast drift to int32_t

Author: Jarkko Paso

source/Service_Libs/fhss/fhss_ws.c

@@ -860,7 +860,7 @@ int fhss_ws_set_parent(fhss_structure_t *fhss_structure, const uint8_t eui64[8],
         //TODO: Compensation for fixed channel configuration
         if (SYNCH_COMPENSATION_MIN_INTERVAL <= US_TO_S(time_since_last_synch_us)) {
             // Update clock drift
-            int32_t drift_per_ms_tmp = divide_integer(MS_TO_NS((true_bc_interval_offset - own_bc_interval_offset) + ((int32_t)(fhss_structure->ws->bc_slot - own_bc_slot) * bc_timing_info->broadcast_interval)), US_TO_MS(time_since_last_synch_us));
+            int32_t drift_per_ms_tmp = divide_integer((int32_t)MS_TO_NS((true_bc_interval_offset - own_bc_interval_offset) + ((int32_t)(fhss_structure->ws->bc_slot - own_bc_slot) * bc_timing_info->broadcast_interval)), US_TO_MS(time_since_last_synch_us));
             if (drift_per_ms_tmp > MAX_DRIFT_COMPENSATION_STEP) {
                 drift_per_ms_tmp = MAX_DRIFT_COMPENSATION_STEP;
             } else if (drift_per_ms_tmp < -MAX_DRIFT_COMPENSATION_STEP) {