net: mctp: Consistent peer address handling in ioctl tag allocation

When executing ioctl to allocate tags, if the peer address is 0,
mctp_alloc_local_tag now replaces it with 0xff. However, during tag
dropping, this replacement is not performed, potentially causing the key
not to be dropped as expected.

Signed-off-by: John Wang <wangzhiqiang02@ieisystem.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://patch.msgid.link/20240730084636.184140-1-wangzhiqiang02@ieisystem.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>