Fix testcase failed

Issue: https://gitee.com/openharmony/third_party_musl/issues/I7TP1Y

test: libc-test
Signed-off-by: Njwx1265790 <2510840462@qq.com>

libc-test/src/functionalext/supplement/misc/forkpty.c

@@ -40,12 +40,13 @@ void forkpty_0100(void)
         fp = fopen("test1.txt", "w+");
         fwrite(sign_r, sizeof(char), strlen(sign_r), fp);
         fclose(fp);
+        exit(EXIT_SUCCESS);
     } else {
+        wait(NULL);
         fp = fopen("test2.txt", "w+");
         fwrite(sign_r, sizeof(char), strlen(sign_r), fp);
         fclose(fp);
-    }
-    sleep(1);
+
         FILE *fp1 = fopen("test1.txt", "r");
         FILE *fp2 = fopen("test2.txt", "r");
         fread(list1, sizeof(list1), 1, fp1);
@@ -56,6 +57,7 @@ void forkpty_0100(void)
         fclose(fp2);
         remove("test1.txt");
         remove("test2.txt");
+    }
 }
 
 int main(int argc, char *argv[])