oprofile: remove unused components in struct oprofile_cpu_buffer

Signed-off-by: Robert Richter <robert.richter@amd.com>

drivers/oprofile/cpu_buffer.c

@@ -97,8 +97,6 @@ int alloc_cpu_buffers(void)
 		b->last_is_kernel = -1;
 		b->tracing = 0;
 		b->buffer_size = buffer_size;
-		b->tail_pos = 0;
-		b->head_pos = 0;
 		b->sample_received = 0;
 		b->sample_lost_overflow = 0;
 		b->backtrace_aborted = 0;

drivers/oprofile/cpu_buffer.h

@@ -40,8 +40,6 @@ struct op_entry {
 };
 
 struct oprofile_cpu_buffer {
-	volatile unsigned long head_pos;
-	volatile unsigned long tail_pos;
 	unsigned long buffer_size;
 	struct task_struct *last_task;
 	int last_is_kernel;