scsi: sr: Don't use GFP_DMA

The allocated buffers are used as a command payload, for which the block
layer and/or DMA API do the proper bounce buffering if needed.

Link: https://lore.kernel.org/r/20211222090842.920724-1-hch@lst.deReported-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/sr.c

@@ -856,7 +856,7 @@ static void get_capabilities(struct scsi_cd *cd)
 
 
 	/* allocate transfer buffer */
-	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
+	buffer = kmalloc(512, GFP_KERNEL);
 	if (!buffer) {
 		sr_printk(KERN_ERR, cd, "out of memory.\n");
 		return;

drivers/scsi/sr_vendor.c

@@ -131,7 +131,7 @@ int sr_set_blocklength(Scsi_CD *cd, int blocklength)
 	if (cd->vendor == VENDOR_TOSHIBA)
 		density = (blocklength > 2048) ? 0x81 : 0x83;
 
-	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
+	buffer = kmalloc(512, GFP_KERNEL);
 	if (!buffer)
 		return -ENOMEM;
 
@@ -179,7 +179,7 @@ int sr_cd_check(struct cdrom_device_info *cdi)
 	if (cd->cdi.mask & CDC_MULTI_SESSION)
 		return 0;
 
-	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
+	buffer = kmalloc(512, GFP_KERNEL);
 	if (!buffer)
 		return -ENOMEM;