ext4: rename {exit,init}_ext4_*() to ext4_{exit,init}_*()

This is a cleanup to avoid namespace leaks out of fs/ext4

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 3a8cd8d..fa4b899 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1588,7 +1588,7 @@
 #undef BLOCK_HASH_SHIFT
 
 int __init
-init_ext4_xattr(void)
+ext4_init_xattr(void)
 {
 	ext4_xattr_cache = mb_cache_create("ext4_xattr", 6);
 	if (!ext4_xattr_cache)
@@ -1597,7 +1597,7 @@
 }
 
 void
-exit_ext4_xattr(void)
+ext4_exit_xattr(void)
 {
 	if (ext4_xattr_cache)
 		mb_cache_destroy(ext4_xattr_cache);