scsi: Change the return type of the .queuecommand() callback

scsi: Change the return type of the .queuecommand() callback

In clang version 21.1 and later the -Wimplicit-enum-enum-cast warning
option has been introduced. This warning is enabled by default and can
be used to catch .queuecommand() implementations that return another
value than 0 or one of the SCSI_MLQUEUE_* constants. Hence this patch
that changes the return type of the .queuecommand() implementations from
'int' into 'enum scsi_qc_status'. No functionality has been changed.

Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260115210357.2501991-6-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>