driver: hv: remove cast for kmalloc return value

remove cast for kmalloc return value.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/hv.c

@@ -289,9 +289,8 @@ void hv_synic_init(void *arg)
 	/* Check the version */
 	rdmsrl(HV_X64_MSR_SVERSION, version);
 
-	hv_context.event_dpc[cpu] = (struct tasklet_struct *)
-					kmalloc(sizeof(struct tasklet_struct),
-						GFP_ATOMIC);
+	hv_context.event_dpc[cpu] = kmalloc(sizeof(struct tasklet_struct),
+					    GFP_ATOMIC);
 	if (hv_context.event_dpc[cpu] == NULL) {
 		pr_err("Unable to allocate event dpc\n");
 		goto cleanup;