[scudo] Always exclude Tag 0

prepareTaggedChunk uses Tag 0 for header.

Android already PR_MTE_TAG_MASK to 0xfffe,
but with the patch we will not need to deppend
on the system configuration.

Reviewed By: pcc

Differential Revision: https://reviews.llvm.org/D103134

GitOrigin-RevId: ba04c7c128b1214edf8888b129f9e841852a629b
1 file changed