i2c: octeon: Prevent error message on bus error

The error message:

[Fri Feb 16 13:42:13 2018] i2c-thunderx 0000:01:09.4: unhandled state: 0

is mis-leading as state 0 (bus error) is not an unknown state.

Return -EIO as before but avoid printing the message. Also rename
STAT_ERROR to STATE_BUS_ERROR.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-octeon-core.c

@@ -233,6 +233,7 @@ static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
 		return -EOPNOTSUPP;
 
 	case STAT_TXDATA_NAK:
+	case STAT_BUS_ERROR:
 		return -EIO;
 	case STAT_TXADDR_NAK:
 	case STAT_RXADDR_NAK:

drivers/i2c/busses/i2c-octeon-core.h

@@ -43,7 +43,7 @@
 #define TWSI_CTL_AAK		0x04	/* Assert ACK */
 
 /* Status values */
-#define STAT_ERROR		0x00
+#define STAT_BUS_ERROR		0x00
 #define STAT_START		0x08
 #define STAT_REP_START		0x10
 #define STAT_TXADDR_ACK		0x18