UefiCpuPkg/CpuDxe: Do not ASSERT on AllocateMemorySpace() error

Platform PEI may add LOCAL APIC memory mapped space into
EFI_HOB_MEMORY_ALLOCATION. Or platform may allocate this range before.

So, we skip AllocateMemorySpace()'s return status checking. Instead, we add one
DEBUG message for possible trace.

https://bugzilla.tianocore.org/show_bug.cgi?id=390

This updating is suggested by Ersek's comments at
https://www.mail-archive.com/edk2-devel@lists.01.org/msg22585.html

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Feng Tian <feng.tian@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>