MdeModulePkg/UdfDxe: Use error handling when fail to return LSN

MdeModulePkg/UdfDxe: Use error handling when fail to return LSN

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1248

This commit will refine the ASSERTs in function GetLongAdLsn() and
GetAllocationDescriptorLsn() when the logical sector number cannot be
returned due to unrecognized media format.

Error handling logic will be used for those ASSERTs.

Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Star Zeng <star.zeng@intel.com>