fs/ntfs3: fix build without CONFIG_NTFS3_LZX_XPRESS

When CONFIG_NTFS3_LZX_XPRESS is not set then we get the following build
error:

  fs/ntfs3/frecord.c:2460:16: error: unused variable ‘i_size’
Signed-off-by: Mark O'Donovan <shiftee@posteo.net>
Fixes: 4fd6c08a ("fs/ntfs3: Use i_size_read and i_size_write")
Tested-by: Chris Clayton <chris2553@googlemail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ntfs3/frecord.c

@@ -2457,7 +2457,6 @@ int ni_read_frame(struct ntfs_inode *ni, u64 frame_vbo, struct page **pages,
 	struct ATTR_LIST_ENTRY *le = NULL;
 	struct runs_tree *run = &ni->file.run;
 	u64 valid_size = ni->i_valid;
-	loff_t i_size = i_size_read(&ni->vfs_inode);
 	u64 vbo_disk;
 	size_t unc_size;
 	u32 frame_size, i, npages_disk, ondisk_size;
@@ -2509,6 +2508,7 @@ int ni_read_frame(struct ntfs_inode *ni, u64 frame_vbo, struct page **pages,
 		err = -EOPNOTSUPP;
 		goto out1;
 #else
+		loff_t i_size = i_size_read(&ni->vfs_inode);
 		u32 frame_bits = ni_ext_compress_bits(ni);
 		u64 frame64 = frame_vbo >> frame_bits;
 		u64 frames, vbo_data;