libata: workaround DRQ=1 ERR=1 for ATAPI tape drives

After an error condition, some ATAPI tape drives set DRQ=1 together
with ERR=1 when asking the host to transfer the CDB of the next packet
command (i.e. request sense).  This patch, a revised version of
Alan/Mark's previous patch, adds ATA_HORKAGE_STUCK_ERR to workaround
the problem by ignoring the ERR bit and proceed sending the CDB.

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Mark Lord <liml@rtr.ca>
Signed-off-by: Tejun Heo <htejun@gmail.com>

include/linux/libata.h

@@ -340,6 +340,7 @@ enum {
 	ATA_HORKAGE_HPA_SIZE	= (1 << 6),	/* native size off by one */
 	ATA_HORKAGE_IPM		= (1 << 7),	/* Link PM problems */
 	ATA_HORKAGE_IVB		= (1 << 8),	/* cbl det validity bit bugs */
+	ATA_HORKAGE_STUCK_ERR	= (1 << 9),	/* stuck ERR on next PACKET */
 
 	 /* DMA mask for user DMA control: User visible values; DO NOT
 	    renumber */