scsi: vmw_pvscsi: Silence dma mapping errors

These errors typically occur with swiotlb when the swiotlb buffer is full.
But they are transient and would typically unnecessarily worry a user.
Instead of errors, print debug messages.

Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20191203193052.7583-2-thomas_os@shipmail.org
Acked-by: Jim Gill <jgill@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/vmw_pvscsi.c

@@ -365,7 +365,7 @@ static int pvscsi_map_buffers(struct pvscsi_adapter *adapter,
 		int segs = scsi_dma_map(cmd);
 
 		if (segs == -ENOMEM) {
-			scmd_printk(KERN_ERR, cmd,
+			scmd_printk(KERN_DEBUG, cmd,
 				    "vmw_pvscsi: Failed to map cmd sglist for DMA.\n");
 			return -ENOMEM;
 		} else if (segs > 1) {
@@ -392,7 +392,7 @@ static int pvscsi_map_buffers(struct pvscsi_adapter *adapter,
 		ctx->dataPA = dma_map_single(&adapter->dev->dev, sg, bufflen,
 					     cmd->sc_data_direction);
 		if (dma_mapping_error(&adapter->dev->dev, ctx->dataPA)) {
-			scmd_printk(KERN_ERR, cmd,
+			scmd_printk(KERN_DEBUG, cmd,
 				    "vmw_pvscsi: Failed to map direct data buffer for DMA.\n");
 			return -ENOMEM;
 		}
@@ -725,7 +725,7 @@ static int pvscsi_queue_ring(struct pvscsi_adapter *adapter,
 				cmd->sense_buffer, SCSI_SENSE_BUFFERSIZE,
 				DMA_FROM_DEVICE);
 		if (dma_mapping_error(&adapter->dev->dev, ctx->sensePA)) {
-			scmd_printk(KERN_ERR, cmd,
+			scmd_printk(KERN_DEBUG, cmd,
 				    "vmw_pvscsi: Failed to map sense buffer for DMA.\n");
 			ctx->sensePA = 0;
 			return -ENOMEM;