common: scheduling-classes: update info about priority

Priority 99 used to be problematic, it is not anymore with current
kernels. Remove this old info.

Move info about the priority to clarify it does not apply to
SCHED_DEADLINE.

Signed-off-by: Luca Ceresoli <[email protected]>

common/scheduling-classes.tex

@@ -27,11 +27,10 @@
 	\frametitle{Realtime Scheduling Classes}
 	There are 3 \textbf{Realtime} classes
 	\begin{itemize}
-		\item Tasks under a Realtime class can be assigned a priority between 0 and 98
-		\item Priority 99 is \textbf{reserved} for critical housekeeping tasks
 		\item Runnable tasks will preempt any other lower-priority task
 		\item \ksym{SCHED_FIFO}: All tasks with the same priority are scheduled \textbf{First in, First out}
 		\item \ksym{SCHED_RR}: Similar to \ksym{SCHED_FIFO} but with a time-sharing round-robin between tasks with the same priority
+		\item Both \ksym{SCHED_FIFO} and \ksym{SCHED_RR} can be assigned a priority between 0 and 99
 		\item \ksym{SCHED_DEADLINE}: For tasks doing recurrent jobs, extra attributes are attached to a task
 			\begin{itemize}
 				\item A computation time, which represents the time the task needs to complete a job