btrfs: Remove extra parentheses from condition in copy_items()

commit 0dde10bed2c44a4024eb446cc72fe4e0cb97ec06 upstream.

There is no need for the extra pair of parentheses, remove it. This
fixes the following warning when building with clang:

fs/btrfs/tree-log.c:3694:10: warning: equality comparison with extraneous
  parentheses [-Wparentheses-equality]
                if ((i == (nr - 1)))
                     ~~^~~~~~~~~~~

Also remove the unnecessary parentheses around the substraction.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 5539f0b..5240173 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3664,7 +3664,7 @@
 
 		src_offset = btrfs_item_ptr_offset(src, start_slot + i);
 
-		if ((i == (nr - 1)))
+		if (i == nr - 1)
 			last_key = ins_keys[i];
 
 		if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {