oprofile: remove irq_flags in struct op_entry

This became obsolete with this commit:

 304cc6a ring_buffer: remove unused flags parameter, fix

Signed-off-by: Robert Richter <robert.richter@amd.com>
diff --git a/include/linux/oprofile.h b/include/linux/oprofile.h
index 1d9518b..dbbe2db 100644
--- a/include/linux/oprofile.h
+++ b/include/linux/oprofile.h
@@ -171,7 +171,6 @@
 struct op_entry {
 	struct ring_buffer_event *event;
 	struct op_sample *sample;
-	unsigned long irq_flags;
 	unsigned long size;
 	unsigned long *data;
 };