Fixed buglets in su/su_alloc.c.
Fixed buglets in su/su_alloc.c.

su_alloc() did zero memory. su_realloc() used su_alloc().

darcs-hash:20051102153357-65a35-223cf6c7a674456a4a24ad0b5194f55ae94d9980.gz

BelledonneCommunications/sofia-sip,unispeech/sofia-sip,xhook/sofia-sip,jart/sofia-sip,jart/sofia-sip,BelledonneCommunications/sofia-sip,BelledonneCommunications/sofia-sip,erdincay/sofia-sip,BelledonneCommunications/sofia-sip,xhook/sofia-sip,unispeech/sofia-sip,jart/sofia-sip,unispeech/sofia-sip,erdincay/sofia-sip,unispeech/sofia-sip,xhook/sofia-sip,erdincay/sofia-sip,erdincay/sofia-sip,xhook/sofia-sip,xhook/sofia-sip