ipmi: ipmb: initialise event handler read bytes

IPMB doesn't use i2c reads, but the handler needs to set a value.
Otherwise an i2c read will return an uninitialised value from the bus
driver.

Fixes: 63c4eb3 ("ipmi:ipmb: Add initial support for IPMI over IPMB")
Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>
Message-ID: <20260113-ipmb-read-init-v1-1-a9cbce7b94e3@codeconstruct.com.au>
Signed-off-by: Corey Minyard <corey@minyard.net>

Author: mkj

drivers/char/ipmi/ipmi_ipmb.c

@@ -202,11 +202,16 @@ static int ipmi_ipmb_slave_cb(struct i2c_client *client,
 		break;
 
 	case I2C_SLAVE_READ_REQUESTED:
+		*val = 0xff;
+		ipmi_ipmb_check_msg_done(iidev);
+		break;
+
 	case I2C_SLAVE_STOP:
 		ipmi_ipmb_check_msg_done(iidev);
 		break;
 
 	case I2C_SLAVE_READ_PROCESSED:
+		*val = 0xff;
 		break;
 	}