oprofile: remove backtrace code for ibs

This code is broken since a TRACE_BEGIN_CODE is never sent to the
daemon. The data becomes corrupt since the backtrace is interpreted as
ibs sample.

Signed-off-by: Robert Richter <robert.richter@amd.com>
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 8ae37c9..92bf8c0 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -347,17 +347,11 @@
 		fail = fail || add_sample(cpu_buf, ibs_sample[10], ibs_sample[11]);
 	}
 
-	if (fail)
-		goto fail;
-
-	if (oprofile_backtrace_depth)
-		oprofile_ops.backtrace(regs, oprofile_backtrace_depth);
-
-	return;
+	if (!fail)
+		return;
 
 fail:
 	cpu_buf->sample_lost_overflow++;
-	return;
 }
 
 #endif