oprofile: remove irq_flags in struct op_entry

This became obsolete with this commit:

 304cc6ae ring_buffer: remove unused flags parameter, fix
Signed-off-by: Robert Richter <robert.richter@amd.com>

include/linux/oprofile.h

@@ -171,7 +171,6 @@ struct op_sample;
 struct op_entry {
 	struct ring_buffer_event *event;
 	struct op_sample *sample;
-	unsigned long irq_flags;
 	unsigned long size;
 	unsigned long *data;
 };