NetworkPkg: Fix suspicious dereference of pointer 'FieldCount'

This patch is used to fix suspicious dereference of pointer 'FieldCount'
before NULL check.

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>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18409 6f19259b-4bc3-4df7-8a09-765794883524
1 file changed