qmp-events: fix GUEST_PANICKED description formatting

Signed-off-by: NAnton Nefedov <anton.nefedov@virtuozzo.com>
Signed-off-by: NDenis V. Lunev <den@openvz.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Eric Blake <eblake@redhat.com>
Message-Id: <1487614915-18710-4-git-send-email-den@openvz.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

qapi/event.json

@@ -488,9 +488,9 @@
 #
 # @action: action that has been taken, currently always "pause"
 #
-# @info: optional information about a panic
+# @info: #optional information about a panic (since 2.9)
 #
-# Since: 1.5 (@info since 2.9)
+# Since: 1.5
 #
 # Example:
 #