ipmi: ssif: Remove finished TODO comment about SMBus alert

commit 9162052173 ("ipmi: Add alert handling to SSIF") introduces
support of SMBus alert. So, just remove TODO comment in order not to
confuse future readers.

Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Message-Id: <20200624065405.17653-2-misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

drivers/char/ipmi/ipmi_ssif.c

@@ -22,11 +22,6 @@
  * and drives the real SSIF state machine.
  */
 
-/*
- * TODO: Figure out how to use SMB alerts.  This will require a new
- * interface into the I2C driver, I believe.
- */
-
 #define pr_fmt(fmt) "ipmi_ssif: " fmt
 #define dev_fmt(fmt) "ipmi_ssif: " fmt