savestring: Rename parameter 'size' to 'len'.

savestring: Rename parameter 'size' to 'len'.

It's better to avoid needless confusion, and call string length,
length, instead of size, which is usually used to refer to sizeof of
the string (len+1):

	size_t len = strlen (str);
	size_t size = sizeof (str);

Tested on x86_64 Fedora 17.

2013-02-14  Pedro Alves  <palves@redhat.com>

	* utils.c (savestring): Rename parameter 'size' to 'len'.