[][Fix coverity check errors for Eth/HNAT driver]

[Description]
Fix coverity check errors for Eth/HNAT driver.
(145 errors corrected)

[Release-log]
N/A

Change-Id: I1f9839918a6bf93c6af4efb07acb82c89b4d8ea2
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5264218
diff --git a/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_dbg.c b/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_dbg.c
index e2bf16f..574440d 100755
--- a/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_dbg.c
+++ b/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_dbg.c
@@ -1220,12 +1220,11 @@
 	char *p_token = NULL;
 	char *p_delimiter = " \t";
 	long x = 0, y = 0;
-	int len = count;
+	u32 len = count;
 	int ret;
 
 	if (len >= sizeof(buf)) {
 		pr_info("Input handling fail!\n");
-		len = sizeof(buf) - 1;
 		return -1;
 	}