MIPS: Loongson2ef: Replace deprecated strncpy() with strscpy()

strncpy() is deprecated for NUL-terminated destination buffers. Use
strscpy() instead and remove the manual NUL-termination.

Compile-tested only.

Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/loongson2ef/common/machtype.c

@@ -48,8 +48,7 @@ void __init prom_init_machtype(void)
 		return;
 	}
 	p += strlen("machtype=");
-	strncpy(str, p, MACHTYPE_LEN);
-	str[MACHTYPE_LEN] = '\0';
+	strscpy(str, p);
 	p = strstr(str, " ");
 	if (p)
 		*p = '\0';