Fix comment into sys/dev/acpi/acpibtn.c

[David Coppa]

I think this comment was copy-pasted as is from the comment some
lines below, but this is about hibernation, not sleep.

Ok?

Index: acpibtn.c
===================================================================
RCS file: /cvs/src/sys/dev/acpi/acpibtn.c,v
retrieving revision 1.44
diff -u -p -u -p -r1.44 acpibtn.c
--- acpibtn.c   2 Mar 2017 10:38:10 -0000       1.44
+++ acpibtn.c   11 May 2017 11:10:21 -0000
@@ -236,7 +236,7 @@ acpibtn_notify(struct aml_node *node, in
                        goto sleep;
 #ifdef HIBERNATE
                case 2:
-                       /* Request to go to sleep */
+                       /* Request hibernation */
                        if (acpi_record_event(sc->sc_acpi, 
APM_USER_HIBERNATE_REQ))
                                acpi_addtask(sc->sc_acpi, acpi_sleep_task,
                                    sc->sc_acpi, ACPI_SLEEP_HIBERNATE);