xfs: change the seconds fields in xfs_bulkstat to signed

64-bit time is a signed quantity in the kernel, so the bulkstat
structure should reflect that.  Note that the structure size stays
the same and that we have not yet published userspace headers for this
new ioctl so there are no users to break.

Fixes: 7035f9724f ("xfs: introduce new v5 bulkstat structure")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/libxfs/xfs_fs.h

@@ -366,11 +366,11 @@ struct xfs_bulkstat {
 	uint64_t	bs_blocks;	/* number of blocks		*/
 	uint64_t	bs_xflags;	/* extended flags		*/
 
-	uint64_t	bs_atime;	/* access time, seconds		*/
-	uint64_t	bs_mtime;	/* modify time, seconds		*/
+	int64_t		bs_atime;	/* access time, seconds		*/
+	int64_t		bs_mtime;	/* modify time, seconds		*/
 
-	uint64_t	bs_ctime;	/* inode change time, seconds	*/
-	uint64_t	bs_btime;	/* creation time, seconds	*/
+	int64_t		bs_ctime;	/* inode change time, seconds	*/
+	int64_t		bs_btime;	/* creation time, seconds	*/
 
 	uint32_t	bs_gen;		/* generation count		*/
 	uint32_t	bs_uid;		/* user id			*/