fix: srand未使用入参，实现存在问题

close: #I3W9ZP
Signed-off-by: Nzff <zhangfanfan2@huawei.com>
Change-Id: Ica4da7311f636d0afe34c5182bef518a62c60cc1

kernel/src/prng/rand.c

 #include <stdlib.h>
 #include <stdint.h>
 
-static uint64_t seed;
-
 void srand(unsigned s)
 {
-    return srandom(seed);
+    return srandom(s);
 }
 
 int rand(void)