Removed -t option and other missing fixes (sonic-net#1884)

- What I did
This PR include some fixes which were missed for sonic-net#1723
i.e. removing -t option from the docker exec commands. to understand why the -it option was removed, refer sonic-net#1723.
Also, the show techsupport exits with $RETURN_CODE only when --redirect-stderr option is used.

Signed-off-by: Vivek Reddy Karri <vkarri@nvidia.com>

scripts/generate_dump

@@ -685,11 +685,11 @@ save_redis() {
 save_saidump() {
     trap 'handle_error $? $LINENO' ERR
     if [[ ( "$NUM_ASICS" == 1 ) ]] ; then
-        save_cmd "docker exec -t syncd saidump" "saidump"
+        save_cmd "docker exec syncd saidump" "saidump"
     else
         for (( i=0; i<$NUM_ASICS; i++ ))
         do
-            save_cmd "docker exec -t syncd$i saidump" "saidump$i"
+            save_cmd "docker exec syncd$i saidump" "saidump$i"
         done
     fi
 }
@@ -830,8 +830,8 @@ collect_mellanox() {
     local sai_dump_folder="/tmp/saisdkdump"
     local sai_dump_filename="${sai_dump_folder}/sai_sdk_dump_$(date +"%m_%d_%Y_%I_%M_%p")"
 
-    ${CMD_PREFIX}docker exec -t syncd mkdir -p $sai_dump_folder
-    ${CMD_PREFIX}docker exec -t syncd saisdkdump -f $sai_dump_filename
+    ${CMD_PREFIX}docker exec syncd mkdir -p $sai_dump_folder
+    ${CMD_PREFIX}docker exec syncd saisdkdump -f $sai_dump_filename
 
     copy_from_docker syncd $sai_dump_folder $sai_dump_folder
     echo "$sai_dump_folder"
@@ -840,7 +840,7 @@ collect_mellanox() {
     done
 
     ${CMD_PREFIX}rm -rf $sai_dump_folder
-    ${CMD_PREFIX}docker exec -t syncd rm -rf $sai_dump_folder
+    ${CMD_PREFIX}docker exec syncd rm -rf $sai_dump_folder
 
     # Save SDK error dumps
     local sdk_dump_path=`${CMD_PREFIX}docker exec syncd cat /tmp/sai.profile|grep "SAI_DUMP_STORE_PATH"|cut -d = -f2`
@@ -1217,12 +1217,12 @@ main() {
     if [[ ( "$NUM_ASICS" > 1 ) ]]; then
         for (( i=0; i<$NUM_ASICS; i++ ))
         do
-            save_cmd "docker exec -t lldp$i lldpcli show statistics" "lldp$i.statistics"
+            save_cmd "docker exec lldp$i lldpcli show statistics" "lldp$i.statistics"
             save_cmd "docker logs bgp$i" "docker.bgp$i.log"
             save_cmd "docker logs swss$i" "docker.swss$i.log"
         done
     else
-        save_cmd "docker exec -t lldp lldpcli show statistics" "lldp.statistics"
+        save_cmd "docker exec lldp lldpcli show statistics" "lldp.statistics"
         save_cmd "docker logs bgp" "docker.bgp.log"
         save_cmd "docker logs swss" "docker.swss.log"
     fi
@@ -1339,7 +1339,11 @@ main() {
     fi
 
     echo ${TARFILE}
-    exit $RETURN_CODE
+
+    if ! $SAVE_STDERR
+    then
+    	exit $RETURN_CODE
+    fi
 }
 
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