The sync update work queue tasks is calling uninterruptible sleep function, which is
causing high CPU load.  Changed to interruptible sleep function.  The stats update
task should be interruptible.

--- a/frontends/nss/ecm_nss_ipv4.c
+++ b.frontends/nss/ecm_nss_ipv4.c
@@ -2411,7 +2411,7 @@ static void ecm_nss_ipv4_stats_sync_req_
 	}
 	spin_unlock_bh(&ecm_nss_ipv4_lock);
 
-	usleep_range(ECM_NSS_IPV4_STATS_SYNC_UDELAY - 100, ECM_NSS_IPV4_STATS_SYNC_UDELAY);
+	msleep_interruptible(ECM_NSS_IPV4_STATS_SYNC_UDELAY / 1000);
 
 	/*
 	 * If index is 0, we are starting a new round, but if we still have time remain
@@ -2425,7 +2425,7 @@ static void ecm_nss_ipv4_stats_sync_req_
 		}
 
 		if (ecm_nss_ipv4_next_req_time > current_jiffies) {
-			msleep(jiffies_to_msecs(ecm_nss_ipv4_next_req_time - current_jiffies));
+			msleep_interruptible(jiffies_to_msecs(ecm_nss_ipv4_next_req_time - current_jiffies));
 		}
 		ecm_nss_ipv4_roll_check_jiffies = jiffies;
 		ecm_nss_ipv4_next_req_time = ecm_nss_ipv4_roll_check_jiffies + ECM_NSS_IPV4_STATS_SYNC_PERIOD;
--- a/frontends/nss/ecm_nss_ipv6.c
+++ b.frontends/nss/ecm_nss_ipv6.c
@@ -2128,7 +2128,7 @@ static void ecm_nss_ipv6_stats_sync_req_
 	}
 	spin_unlock_bh(&ecm_nss_ipv6_lock);
 
-	usleep_range(ECM_NSS_IPV6_STATS_SYNC_UDELAY - 100, ECM_NSS_IPV6_STATS_SYNC_UDELAY);
+	msleep_interruptible(ECM_NSS_IPV6_STATS_SYNC_UDELAY / 1000);
 
 	/*
 	 * If index is 0, we are starting a new round, but if we still have time remain
@@ -2142,7 +2142,7 @@ static void ecm_nss_ipv6_stats_sync_req_
 		}
 
 		if (ecm_nss_ipv6_next_req_time > current_jiffies) {
-			msleep(jiffies_to_msecs(ecm_nss_ipv6_next_req_time - current_jiffies));
+			msleep_interruptible(jiffies_to_msecs(ecm_nss_ipv6_next_req_time - current_jiffies));
 		}
 		ecm_nss_ipv6_roll_check_jiffies = jiffies;
 		ecm_nss_ipv6_next_req_time = ecm_nss_ipv6_roll_check_jiffies + ECM_NSS_IPV6_STATS_SYNC_PERIOD;