Btrfs: fix compiles when CONFIG_BTRFS_FS_RUN_SANITY_TESTS is off

Commit fccb84c9 moved added some helpers to cleanup our sanity tests,
but it looks like both Dave and I always compile with the tests enabled.

This fixes things to work when they are turned off too.
Signed-off-by: NChris Mason <clm@fb.com>

fs/btrfs/ctree.h

@@ -1818,9 +1818,8 @@ struct btrfs_root {
 
 	u64 highest_objectid;
 
-#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+	/* only used with CONFIG_BTRFS_FS_RUN_SANITY_TESTS is enabled */
 	u64 alloc_bytenr;
-#endif
 
 	u64 defrag_trans_start;
 	struct btrfs_key defrag_progress;

fs/btrfs/extent_io.h

@@ -374,7 +374,7 @@ noinline u64 find_lock_delalloc_range(struct inode *inode,
 				      struct extent_io_tree *tree,
 				      struct page *locked_page, u64 *start,
 				      u64 *end, u64 max_bytes);
+#endif
 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
 					       u64 start, unsigned long len);
 #endif
-#endif