ext4: remove duplicated declarations in inode.c

In patch cb20d5188366f04d96d2e07b1240cc92170ade40, ext4_set_bh_endio
and ext4_end_io_buffer_write are declared at the beginning of inode.c,
and again later on in the middle of the file.  Remove the second set
of duplicated function declarations.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 6324f74e..b4effbd 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1954,9 +1954,6 @@
 	return ret;
 }
 
-static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode);
-static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
-
 /*
  * Note that we don't need to start a transaction unless we're journaling data
  * because we should have holes filled from ext4_page_mkwrite(). We even don't