btrfs: free-space-cache.c: remove extra semicolon.

The patch below removes an extra semicolon.
Signed-off-by: NJustin P. Mattock <justinmattock@gmail.com>
CC: Chris Mason <chris.mason@oracle.com>
CC: linux-btrfs@vger.kernel.org
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

fs/btrfs/free-space-cache.c

@@ -418,7 +418,7 @@ static void io_ctl_set_crc(struct io_ctl *io_ctl, int index)
 	}
 
 	if (index == 0)
-		offset = sizeof(u32) * io_ctl->num_pages;;
+		offset = sizeof(u32) * io_ctl->num_pages;
 
 	crc = btrfs_csum_data(io_ctl->root, io_ctl->orig + offset, crc,
 			      PAGE_CACHE_SIZE - offset);