NetworkPkg: Removing or adding some ASSERT statement

NetworkPkg: Removing or adding some ASSERT statement

Refine the code by removing or adding some ASSERT statement
to make the code more readable.

Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Ye Ting  <ting.ye@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19592 6f19259b-4bc3-4df7-8a09-765794883524