The 'orig_size' local variable is only used in a call to
mb_debug().  Mark it with '__maybe_unused'.
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
        struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
        int bsbits, max;
        ext4_lblk_t end;
-       loff_t size, orig_size, start_off;
+       loff_t size, start_off;
+       loff_t orig_size __maybe_unused;
        ext4_lblk_t start;
        struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
        struct ext4_prealloc_space *pa;