MAX_LFS_FILESIZE should be a loff_t

fs/nfs/internal.h: In function ‘nfs_super_set_maxbytes’:
fs/nfs/internal.h:547:21: warning: comparison between signed and
    unsigned integer expressions [-Wsign-compare]

Seen with gcc (GCC) 4.6.3 20120306 (Red Hat 4.6.3-2).

Commit 42cb56ae made s_maxbytes a loff_t, thus the type of
MAX_LFS_FILESIZE should also be a loff_t.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

include/linux/fs.h

@@ -1130,9 +1130,9 @@ static inline int file_check_writeable(struct file *filp)
 /* Page cache limit. The filesystems should put that into their s_maxbytes 
    limits, otherwise bad things can happen in VM. */ 
 #if BITS_PER_LONG==32
-#define MAX_LFS_FILESIZE	(((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) 
+#define MAX_LFS_FILESIZE	(((loff_t)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) 
 #elif BITS_PER_LONG==64
-#define MAX_LFS_FILESIZE 	0x7fffffffffffffffUL
+#define MAX_LFS_FILESIZE 	((loff_t)0x7fffffffffffffff)
 #endif
 
 #define FL_POSIX	1