[SCSI] st: Remove bogus memset

Mike Christie noticed a bogus memset. It can be removed as dead code
since the number of bytes in the driver buffer in fixed block mode is
always a multiple of the tape block size.

Signed-off-by: Kai Mäkisara <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/st.c

···
 /* Flush the write buffer (never need to write if variable blocksize). */
 static int st_flush_write_buffer(struct scsi_tape * STp)
 {
-	int offset, transfer, blks;
+	int transfer, blks;
 	int result;
 	unsigned char cmd[MAX_COMMAND_SIZE];
 	struct st_request *SRpnt;
···
 	result = 0;
 	if (STp->dirty == 1) {
 
-		offset = (STp->buffer)->buffer_bytes;
-		transfer = ((offset + STp->block_size - 1) /
-			    STp->block_size) * STp->block_size;
+		transfer = STp->buffer->buffer_bytes;
                 DEBC(printk(ST_DEB_MSG "%s: Flushing %d bytes.\n",
                                tape_name(STp), transfer));
-
-		memset((STp->buffer)->b_data + offset, 0, transfer - offset);
 
 		memset(cmd, 0, MAX_COMMAND_SIZE);
 		cmd[0] = WRITE_6;