fs/ecryptfs/: possible cleanups

- make the following needlessly global code static:
  - crypto.c:ecryptfs_lower_offset_for_extent()
  - crypto.c:key_tfm_list
  - crypto.c:key_tfm_list_mutex
  - inode.c:ecryptfs_getxattr()
  - main.c:ecryptfs_init_persistent_file()

- remove the no longer used mmap.c:ecryptfs_lower_page_cache

- #if 0 the unused read_write.c:ecryptfs_read()

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 5a71918..ed0ed84 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -954,7 +954,7 @@
 	return rc;
 }
 
-ssize_t
+static ssize_t
 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
 		  size_t size)
 {