csiostor uses function pointer casts to keep the csio_ln_ev state machine
hidden, but this causes warnings about control flow integrity (KCFI)
violations in clang-16 and higher:

drivers/scsi/csiostor/csio_lnode.c:1098:33: error: cast from 'void (*)(struct csio_lnode *, enum csio_ln_ev)' to 'csio_sm_state_t' (aka 'void (*)(void *, unsigned int)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
 1098 |         return (csio_get_state(ln) == ((csio_sm_state_t)csio_lns_ready));
      |                                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/csiostor/csio_lnode.c:1369:29: error: cast from 'void (*)(struct csio_lnode *, enum csio_ln_ev)' to 'csio_sm_state_t' (aka 'void (*)(void *, unsigned int)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
 1369 |         if (csio_get_state(ln) == ((csio_sm_state_t)csio_lns_uninit)) {
      |                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/csiostor/csio_lnode.c:1373:29: error: cast from 'void (*)(struct csio_lnode *, enum csio_ln_ev)' to 'csio_sm_state_t' (aka 'void (*)(void *, unsigned int)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
 1373 |         if (csio_get_state(ln) == ((csio_sm_state_t)csio_lns_ready)) {
      |                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/csiostor/csio_lnode.c:1377:29: error: cast from 'void (*)(struct csio_lnode *, enum csio_ln_ev)' to 'csio_sm_state_t' (aka 'void (*)(void *, unsigned int)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
 1377 |         if (csio_get_state(ln) == ((csio_sm_state_t)csio_lns_offline)) {
      |                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Move the enum into a shared header so the correct types can be used without
the need for casts.

Fixes: a3667aae ("[SCSI] csiostor: Chelsio FCoE offload driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240213100518.457623-1-arnd@kernel.orgSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>