malloc.c: fix copy-pasted comment from the Dawn Of Time.

My standard 'abort on failure' wrappers around malloc and friends look
more or less the same in most of my C software. In this case, they
were so much the same that there was even a comment betraying that I
copy-pasted them from Halibut. And nobody has noticed in the whole
lifetime of this code base :-)

malloc.c

@@ -7,7 +7,7 @@
 #include "puzzles.h"
 
 /*
- * smalloc should guarantee to return a useful pointer - Halibut
+ * smalloc should guarantee to return a useful pointer - we
  * can do nothing except die when it's out of memory anyway.
  */
 void *smalloc(size_t size) {