Fix a typo in mellanox_buffer_migrator (sonic-net#1090)

This type causes the db_migrator to update the buffer profiles even if they don't match the default

Signed-off-by: Stephen Sun <stephens@nvidia.com>

scripts/mellanox_buffer_migrator.py

@@ -354,7 +354,7 @@ def mlnx_migrate_buffer_profile(self, old_version, new_version):
             return True
 
         for name, profile in buffer_profile_old_configure.iteritems():
-            if name in buffer_profile_conf.keys() and profile == buffer_profile_old_configure[name]:
+            if name in buffer_profile_conf.keys() and profile == buffer_profile_conf[name]:
                 continue
             # return if any default profile isn't in cofiguration
             log.log_notice("Default profile {} isn't in database or doesn't match default value".format(name))
@@ -363,3 +363,5 @@ def mlnx_migrate_buffer_profile(self, old_version, new_version):
         for name, profile in buffer_profile_new_configure.iteritems():
             log.log_info("Successfully migrate profile {}".format(name))
             self.configDB.set_entry('BUFFER_PROFILE', name, profile)
+
+        return True