dmaengine: idxd: remove set but not used variable 'group'

drivers/dma/idxd/sysfs.c: In function engine_group_id_store:
drivers/dma/idxd/sysfs.c:419:29: warning: variable group set but not used [-Wunused-but-set-variable]

It is not used, so remove it.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20200211135335.55924-1-yuehaibing@huawei.comSigned-Off-By: Vinod Koul <vkoul@kernel.org>

drivers/dma/idxd/sysfs.c

@@ -416,7 +416,7 @@ static ssize_t engine_group_id_store(struct device *dev,
 	struct idxd_device *idxd = engine->idxd;
 	long id;
 	int rc;
-	struct idxd_group *prevg, *group;
+	struct idxd_group *prevg;
 
 	rc = kstrtol(buf, 10, &id);
 	if (rc < 0)
@@ -436,7 +436,6 @@ static ssize_t engine_group_id_store(struct device *dev,
 		return count;
 	}
 
-	group = &idxd->groups[id];
 	prevg = engine->group;
 
 	if (prevg)