mtdparts: Fix final outstanding issue reported by Coverity

As part of fixing the previously reported issues, it was missed that in
the case of mtdparts_init() we need to make sure that tmp_ep is long
enough to contain PARTITION_MAXLEN and a NULL termination.  Then, to be
sure the buffer is NULL terminated, zero the entire buffer rather than
just ensuring the first character is NULL.

Cc: Lothar Waßmann <LW@KARO-electronics.de>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Reported-by: Coverity (CID: 166329)
Signed-off-by: NTom Rini <trini@konsulko.com>

cmd/mtdparts.c

@@ -1726,7 +1726,7 @@ int mtdparts_init(void)
 	const char *ids, *parts;
 	const char *current_partition;
 	int ids_changed;
-	char tmp_ep[PARTITION_MAXLEN];
+	char tmp_ep[PARTITION_MAXLEN + 1];
 	char tmp_parts[MTDPARTS_MAXLEN];
 
 	debug("\n---mtdparts_init---\n");
@@ -1750,7 +1750,7 @@ int mtdparts_init(void)
 
 	/* save it for later parsing, cannot rely on current partition pointer
 	 * as 'partition' variable may be updated during init */
-	tmp_ep[0] = '\0';
+	memset(tmp_parts, 0, sizeof(tmp_parts));
 	if (current_partition)
 		strncpy(tmp_ep, current_partition, PARTITION_MAXLEN);