This patch adds formatting error overlay 0x21 to improve debug capabilities.

[jejb: checkpatch fixes]
Signed-off-by: NWen Xiong <wenxiong@linux.vnet.ibm.com>
Acked-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>