MdeModulePkg: Convert HiiDatabaseDxe ConfigRouting ASSERT to return an error

MdeModulePkg: Convert HiiDatabaseDxe ConfigRouting ASSERT to return an error

This should just return an error and not assert.  We hit this when testing with a client that was trying to access the old IP4_CONFIG on firmware implementing IP4_CONFIG2.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Eugene Cohen <eugene@hp.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19219 6f19259b-4bc3-4df7-8a09-765794883524