bugfix: 修复浮点数打印错误的bug

user/libs/libc/math/pow.c

@@ -0,0 +1,10 @@
+#include "math.h"
+#include <libc/stddef.h>
+
+int64_t pow(int64_t x, int y)
+{
+    int64_t res = 1;
+    for (int i = 0; i < y; ++i)
+        res *= x;
+    return res;
+}