arm64: mte: change PR_MTE_TCF_NONE back into an unsigned long

This constant was previously an unsigned long, but was changed
into an int in commit 433c38f40f6a ("arm64: mte: change ASYNC and
SYNC TCF settings into bitfields"). This ended up causing spurious
unsigned-signed comparison warnings in expressions such as:

(x & PR_MTE_TCF_MASK) != PR_MTE_TCF_NONE

Therefore, change it back into an unsigned long to silence these
warnings.

Link: https://linux-review.googlesource.com/id/I07a72310db30227a5b7d789d0b817d78b657c639
Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://lore.kernel.org/r/20211105230829.2254790-1-pcc@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2 files changed