scsi: cxlflash: Fix vlun resize failure in the shrink path

The ioctl DK_CAPI_VLUN_RESIZE can fail if the allocated vlun size is
reduced from almost maximum capacity and then increased again.

The shrink_lxt() routine is currently using the SISL_ASTATUS_MASK to
mask the higher 48 bits of the lxt entry. This is unnecessary and
incorrect as it uses a mask designed for the asynchronous interrupt
status register.  When the 4 port support was added to cxlflash, the
SISL_ASTATUS_MASK was updated to reflect the status bits for all 4
ports. This change indirectly affected the shrink_lxt() code path.

To extract the base, simply shift the bits without masking.

Fixes: 56518072 ("scsi: cxlflash: SISlite updates to support 4 ports")
Signed-off-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/cxlflash/vlun.c

@@ -694,11 +694,7 @@ static int shrink_lxt(struct afu *afu,
 	/* Free LBAs allocated to freed chunks */
 	mutex_lock(&blka->mutex);
 	for (i = delta - 1; i >= 0; i--) {
-		/* Mask the higher 48 bits before shifting, even though
-		 * it is a noop
-		 */
-		aun = (lxt_old[my_new_size + i].rlba_base & SISL_ASTATUS_MASK);
-		aun = (aun >> MC_CHUNK_SHIFT);
+		aun = lxt_old[my_new_size + i].rlba_base >> MC_CHUNK_SHIFT;
 		if (needs_ws)
 			write_same16(sdev, aun, MC_CHUNK_SIZE);
 		ba_free(&blka->ba_lun, aun);