scsi: target: sbp: Remove KMSG_COMPONENT macro

scsi: target: sbp: Remove KMSG_COMPONENT macro

The KMSG_COMPONENT macro is a leftover of the s390 specific "kernel
message catalog" from 2008 [1] which never made it upstream.

The macro was added to s390 code to allow for an out-of-tree patch which
used this to generate unique message ids. Also this out-of-tree doesn't
exist anymore.

The pattern of how the KMSG_COMPONENT is used was partially also used
for non s390 specific code, for whatever reasons.

Remove the macro in order to get rid of a pointless indirection.

[1] https://lwn.net/Articles/292650/

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://patch.msgid.link/20251126144027.2213895-1-hca@linux.ibm.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>