sched/deadline: Change sched_getparam() behaviour vs SCHED_DEADLINE
sched/deadline: Change sched_getparam() behaviour vs SCHED_DEADLINE

The way we read POSIX one should only call sched_getparam() when
sched_getscheduler() returns either SCHED_FIFO or SCHED_RR.

Given that we currently return sched_param::sched_priority=0 for all
others, extend the same behaviour to SCHED_DEADLINE.

Requested-by: Michael Kerrisk <cc9a9bf9e3f3b546e69143652ae261619ab7ca78@gmail.com>
Signed-off-by: Peter Zijlstra <3fddac958924aef220f202ca567388ddab3f14a8@infradead.org>
Acked-by: Michael Kerrisk <cc9a9bf9e3f3b546e69143652ae261619ab7ca78@gmail.com>
Cc: Dario Faggioli <d76701c8994d429ae27f3beb6ae5506d2b99b818@linux.it>
Cc: linux-man <ea86d8e41b7d26def1816698c2779a6288501f19@vger.kernel.org>
Cc: "Michael Kerrisk (man-pages)" <cc9a9bf9e3f3b546e69143652ae261619ab7ca78@gmail.com>
Cc: Juri Lelli <bdc6bcd4e8b34b4b92413d758024aeca6da0e459@gmail.com>
Cc: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>
Cc: <4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org>
Link: 3081e3c42f9c39d865e5eaf59ad7c5d34130f760@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@kernel.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs