x86, bts: provide in-kernel branch-trace interface

Impact: cleanup

Move the BTS bits from ptrace.c into ds.c.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4b81fc5..dc5ea65 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1176,6 +1176,7 @@
 	 * The buffer to hold the BTS data.
 	 */
 	void *bts_buffer;
+	size_t bts_size;
 #endif /* CONFIG_X86_PTRACE_BTS */
 
 	/* PID/PID hash table linkage. */