sched/vtime: Clarify vtime_task_switch() argument layout

This function deals with the previous and next tasks during a context
switch. But only the previous is passed as an argument, the next task
being deduced from current. Make the code clearer by passing both
previous and next as arguments.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Ingo Molnar <mingo@kernel.org>
7 files changed