orangefs: rename remaining bits of mmap readahead cache

This has been dormant code for many years. Parts of it were removed from
the OrangeFS kernel code when it went into mainline. These bits were missed.
Now the readahead cache has been resurrected in the OrangeFS userspace
portions. It was renamed there, since it doesn't really have anything to do
with mmap specifically, so it will be renamed here.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
diff --git a/fs/orangefs/upcall.h b/fs/orangefs/upcall.h
index 001b202..93965fb 100644
--- a/fs/orangefs/upcall.h
+++ b/fs/orangefs/upcall.h
@@ -98,7 +98,7 @@
 	__s64 size;
 };
 
-struct orangefs_mmap_ra_cache_flush_request_s {
+struct orangefs_ra_cache_flush_request_s {
 	struct orangefs_object_kref refn;
 };
 
@@ -228,7 +228,7 @@
 		struct orangefs_rename_request_s rename;
 		struct orangefs_statfs_request_s statfs;
 		struct orangefs_truncate_request_s truncate;
-		struct orangefs_mmap_ra_cache_flush_request_s ra_cache_flush;
+		struct orangefs_ra_cache_flush_request_s ra_cache_flush;
 		struct orangefs_fs_mount_request_s fs_mount;
 		struct orangefs_fs_umount_request_s fs_umount;
 		struct orangefs_getxattr_request_s getxattr;