arm64: Fix task tracing

For accurate accounting call contextidr_thread_switch before a
task is scheduled, rather than after, when the 'next' variable has a
different meaning since we switched the stacks.
Signed-off-by: NChristopher Covington <cov@codeaurora.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/process.c

@@ -311,11 +311,11 @@ struct task_struct *__switch_to(struct task_struct *prev,
 	fpsimd_thread_switch(next);
 	tls_thread_switch(next);
 	hw_breakpoint_thread_switch(next);
+	contextidr_thread_switch(next);
 
 	/* the actual thread switch */
 	last = cpu_switch_to(prev, next);
 
-	contextidr_thread_switch(next);
 	return last;
 }