[SCSI] pmcraid: remove duplicate struct member

sense_buffer is both a direct member of struct pmcraid_cmd as well as
an indirect one via an anonymous union and struct. Fix this clash by
eliminating the direct member in favour of the anonymous struct/union
one. The name duplication apparently isn't noticed by gcc versions
earlier than 4.4

Reported-by: Andi Kleen <[e-mail]>
Signed-off-by: Anil Ravindranath <[e-mail]>
Cc: Stable Tree <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/pmcraid.h

···
 	struct pmcraid_control_block *ioa_cb;
 	dma_addr_t ioa_cb_bus_addr;
 	dma_addr_t dma_handle;
-	u8 *sense_buffer;
 
 	/* pointer to mid layer structure of SCSI commands */
 	struct scsi_cmnd *scsi_cmd;