greybus: connection: replace custom error function with dev_err

Remove custom connection error function and replace it with dev_err.

The standard error function provides more information in the message
prefix (e.g. includes the interface id), has a well-known semantics
(e.g. does does not add newlines to messages), and is even somewhat
shorter to type.

Note that some uses of the custom function were already adding double
newlines due to the non-standard semantics.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
diff --git a/drivers/staging/greybus/spi.c b/drivers/staging/greybus/spi.c
index ad0c179..639c9cd 100644
--- a/drivers/staging/greybus/spi.c
+++ b/drivers/staging/greybus/spi.c
@@ -143,9 +143,8 @@
 	/* Find number of transfers queued and tx/rx length in the message */
 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
 		if (!xfer->tx_buf && !xfer->rx_buf) {
-			gb_connection_err(connection,
-					  "Bufferless transfer, length %u\n",
-					  xfer->len);
+			dev_err(&connection->dev,
+				"bufferless transfer, length %u\n", xfer->len);
 			return NULL;
 		}
 
@@ -160,8 +159,8 @@
 
 	/* Too many transfers ? */
 	if (count > (u32)U16_MAX) {
-		gb_connection_err(connection, "transfer count (%u) too big",
-				  count);
+		dev_err(&connection->dev, "transfer count (%u) too big\n",
+			count);
 		return NULL;
 	}
 
@@ -382,7 +381,7 @@
 	/* Allocate master with space for data */
 	master = spi_alloc_master(&connection->dev, sizeof(*spi));
 	if (!master) {
-		gb_connection_err(connection, "cannot alloc SPI master\n");
+		dev_err(&connection->dev, "cannot alloc SPI master\n");
 		return -ENOMEM;
 	}