QuickJS: fixed non-NULL terminated strings formatting in exceptions.

QuickJS: fixed non-NULL terminated strings formatting in exceptions.

When "%*s" is specified, the first integer is interpreted as width.
Width specifies *minimum* number of characters to output. The next
string is expected to be NULL-terminated.

When "%.*s" is specified, the first integer is interpreted as precision.
Precision specifies *maximum* number of characters to output.