xfs: don't cast string literals

The commit:

a9273ca5 xfs: convert attr to use unsigned names

added these (unsigned char *) casts, but then the _SIZE macros
return "7" - size of a pointer minus one - not the length of
the string.  This is harmless in the kernel, because the _SIZE
macros are not used, but as we sync up with userspace, this will
matter.

I don't think the cast is necessary; i.e. assigning the string
literal to an unsigned char *, or passing it to a function
expecting an unsigned char *, should be ok, right?
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

fs/xfs/libxfs/xfs_format.h

@@ -1453,8 +1453,8 @@ struct xfs_acl {
 		sizeof(struct xfs_acl_entry) * XFS_ACL_MAX_ENTRIES((mp)))
 
 /* On-disk XFS extended attribute names */
-#define SGI_ACL_FILE		(unsigned char *)"SGI_ACL_FILE"
-#define SGI_ACL_DEFAULT		(unsigned char *)"SGI_ACL_DEFAULT"
+#define SGI_ACL_FILE		"SGI_ACL_FILE"
+#define SGI_ACL_DEFAULT		"SGI_ACL_DEFAULT"
 #define SGI_ACL_FILE_SIZE	(sizeof(SGI_ACL_FILE)-1)
 #define SGI_ACL_DEFAULT_SIZE	(sizeof(SGI_ACL_DEFAULT)-1)