Revert, because off64_t isn't available w/o LFS defines;
upstream this needs to be handled seamlessly but we don't
want to change existing RHEL behavior for code that includes
xfs.h

commit cb898f157f8410a03cf5f3400baa1df9e5eecd33
Author: Felix Janda <felix.janda@posteo.de>
Date:   Fri Feb 5 08:34:06 2016 +1100

    linux.h: Use off64_t instead of loff_t
    
    These are equivalent on glibc, while musl does not know loff_t.
    
    In the long run, it would be preferable to enable transparent LFS so
    that off64_t could be replaced by off_t.
    
    Signed-off-by: Felix Janda <felix.janda@posteo.de>
    Reviewed-by: Christoph Hellwig <hch@lst.de>
    Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/include/linux.h b/include/linux.h
index 674717c..a7d2f85 100644
--- a/include/linux.h
+++ b/include/linux.h
@@ -141,7 +141,7 @@ platform_discard_blocks(int fd, uint64_t start, uint64_t len)
 #define EFSCORRUPTED	EUCLEAN	/* Filesystem is corrupted */
 #define EFSBADCRC	EBADMSG	/* Bad CRC detected */
 
-typedef off64_t		xfs_off_t;
+typedef loff_t		xfs_off_t;
 typedef __uint64_t	xfs_ino_t;
 typedef __uint32_t	xfs_dev_t;
 typedef __int64_t	xfs_daddr_t;