ext4: remove duplicated #include of dax.h in inode.c

Fix following includecheck warning:
./fs/ext4/inode.c: linux/dax.h is included more than once.

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Yang Li <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

Author: Yang Li

fs/ext4/inode.c

@@ -41,7 +41,6 @@
 #include <linux/bitops.h>
 #include <linux/iomap.h>
 #include <linux/iversion.h>
-#include <linux/dax.h>
 
 #include "ext4_jbd2.h"
 #include "xattr.h"