[XFS] Remove unused HAVE_SPLICE macro.

HAVE_SPLICE was part of the infrastructure for building 2.4 and 2.6
kernels out of the same tree. Now we don't build 2.4 kernels this

SGI-PV: 971046
SGI-Modid: xfs-linux-melb:xfs-kern:30878a
Signed-off-by: NDonald Douwsma <donaldd@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

fs/xfs/xfs.h

@@ -22,7 +22,7 @@
 #define STATIC
 #define DEBUG 1
 #define XFS_BUF_LOCK_TRACKING 1
-/* #define QUOTADEBUG 1 */
+#define QUOTADEBUG 1
 #endif
 
 #ifdef CONFIG_XFS_TRACE