pktgen: Specify the index of first thread

Use "-f <num>", to specify the index of the first
sender thread.
In default first thread is #0.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/samples/pktgen/pktgen_sample05_flow_per_thread.sh b/samples/pktgen/pktgen_sample05_flow_per_thread.sh
index f4fb794..ac9cfd6 100755
--- a/samples/pktgen/pktgen_sample05_flow_per_thread.sh
+++ b/samples/pktgen/pktgen_sample05_flow_per_thread.sh
@@ -30,7 +30,7 @@
 pg_ctrl "reset"
 
 # Threads are specified with parameter -t value in $THREADS
-for ((thread = 0; thread < $THREADS; thread++)); do
+for ((thread = $F_THREAD; thread <= $L_THREAD; thread++)); do
     dev=${DEV}@${thread}
 
     # Add remove all other devices and add_device $dev to thread
@@ -66,7 +66,7 @@
 # Run if user hits control-c
 function print_result() {
     # Print results
-    for ((thread = 0; thread < $THREADS; thread++)); do
+    for ((thread = $F_THREAD; thread <= $L_THREAD; thread++)); do
 	dev=${DEV}@${thread}
 	echo "Device: $dev"
 	cat /proc/net/pktgen/$dev | grep -A2 "Result:"