staging: comedi: drivers: s626.c - fixed checkpatch issue about data type

staging: comedi: drivers: s626.c - fixed the following checkpatch issue:
CHECK: Prefer kernel type 's16' over 'int16_t'
#1939: FILE: drivers/staging/comedi/drivers/s626.c:1939:
+               int16_t dacdata = (int16_t)data[i];

Signed-off-by: Andrea della Porta <sfaragnaus@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/s626.c

@@ -1936,7 +1936,7 @@ static int s626_ao_insn_write(struct comedi_device *dev,
 	int i;
 
 	for (i = 0; i < insn->n; i++) {
-		int16_t dacdata = (int16_t)data[i];
+		s16 dacdata = (s16)data[i];
 		int ret;
 
 		dacdata -= (0x1fff);