Prevent profile creation for invalid cable length

Added a check in BufferMgrDynamic::allocateProfile to skip profile
creation when the cable length is 0m.
This change ensures that profiles are not created for invalid cable
lengths, preventing potential configuration errors.
Logged a notice message when skipping profile creation due to 0m
cable length.

Signed-off-by: Jianyue Wu <jianyuew@nvidia.com>

Author: jianyuewu

cfgmgr/buffermgrdyn.cpp

@@ -944,6 +944,11 @@ void BufferMgrDynamic::updateBufferObjectListToDb(const string &key, const strin
 // We have to check the headroom ahead of applying them
 task_process_status BufferMgrDynamic::allocateProfile(const string &speed, const string &cable_len, const string &mtu, const string &threshold, const string &gearbox_model, long lane_count, string &profile_name)
 {
+    if (cable_len == "0m")
+    {
+        SWSS_LOG_NOTICE("Skipping profile creation for cable length '0m'");
+        return task_process_status::task_success;
+    }
     // Create record in BUFFER_PROFILE table
 
     SWSS_LOG_INFO("Allocating new BUFFER_PROFILE %s", profile_name.c_str());