scsi: pcmcia: nsp_cs: Remove unused variable 'dummy'

scsi: pcmcia: nsp_cs: Remove unused variable 'dummy'

There is no need to populate an unused variable, even if the read is
required.

Fixes the following W=1 kernel build warning(s):

 drivers/scsi/pcmcia/nsp_cs.c: In function ‘nsp_cs_message’:
 drivers/scsi/pcmcia/nsp_cs.c:143:2: warning: function ‘nsp_cs_message’ might be a candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
 drivers/scsi/pcmcia/nsp_cs.c: In function ‘nsp_fifo_count’:
 drivers/scsi/pcmcia/nsp_cs.c:692:24: warning: variable ‘dummy’ set but not used [-Wunused-but-set-variable]

Link: https://lore.kernel.org/r/20200707140055.2956235-9-lee.jones@linaro.org
Cc: YOKOTA Hiroshi <yokota@netlab.is.tsukuba.ac.jp>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>