[CBRD-24788] backport of #4336 to 11.0 - Add defense code to prevent core dump due to uninitialized pointer variable in csql

[airnet73]

http://jira.cubrid.org/browse/CBRD-24788

Purpose

• backport of [CBRD-24788] Add defense code to prevent core dump due to uninitialized pointer variable in csql #4336 to release/11.0
• In csql, a pointer variable was declared but not initialized.
  Since these uninitialized variables have garbage values, using these variables can cause a core dump.
  Since this variable is used only in the for loop, it must be declared and initialized in the for loop.

Implementation
N/A

Remarks
N/A