Revert "Add FW dump with new SAI implementation (sonic-net#1338)" (so…

…nic-net#1407)

This reverts commit b10622e.

**What I did**
revert changes to call sdkdump and replace with old call to mstdump

**How I did it**
reverting a previous commit [Mellanox] Add FW dump with new SAI implementation and remove mst dump sonic-net#1338

**How to verify it**
run techsupport

scripts/generate_dump

@@ -711,12 +711,11 @@ collect_mellanox() {
     ${CMD_PREFIX}docker exec syncd tar Ccf $(dirname $sai_dump_filename) - $(basename $sai_dump_filename) | tar Cxf /tmp/ -
     save_file $sai_dump_filename sai_sdk_dump true
 
-    file_list_string=$(${CMD_PREFIX}docker exec -it syncd ls -l /tmp | grep sdkdump | awk '{print $9}' | tr -d '\r')
-    file_list_array=( $file_list_string )
-    for element in "${file_list_array[@]}"
-    do
-        docker cp syncd:/tmp/$element /tmp
-        save_file /tmp/$element sai_sdk_dump true
+    local mst_dump_filename="/tmp/mstdump"
+    local max_dump_count="3"
+    for i in $(seq 1 $max_dump_count); do
+        ${CMD_PREFIX}/usr/bin/mstdump /dev/mst/mt*conf0 > "${mst_dump_filename}${i}"
+        save_file "${mst_dump_filename}${i}" mstdump true
     done
 }