[arch][x86][32] fix a bug in the exception report
[arch][x86][32] fix a bug in the exception report

Some of the 16 bit values the cpu pushes on the stack are aligned to
32bit offsets but actually only 16 bits were pushed. Make sure printf
masks off the top 16 bits when printing these fields out.

littlekernel/lk,littlekernel/lk,littlekernel/lk,littlekernel/lk