Cleanup the x-allocation functions

xmalloc() and xrealloc() now take their sizes as size_t-type arguments.
Introduced complementary xcalloc().
Signed-off-by: NBrad Roberts <braddr@puremagic.com>
Signed-off-by: NPetr Baudis <pasky@ucw.cz>

cache.h

@@ -179,7 +179,7 @@ const char *show_date(unsigned long time, int timezone);
 void parse_date(char *date, char *buf, int bufsize);
 void datestamp(char *buf, int bufsize);
 
-static inline void *xmalloc(int size)
+static inline void *xmalloc(size_t size)
 {
 	void *ret = malloc(size);
 	if (!ret)
@@ -187,7 +187,7 @@ static inline void *xmalloc(int size)
 	return ret;
 }
 
-static inline void *xrealloc(void *ptr, int size)
+static inline void *xrealloc(void *ptr, size_t size)
 {
 	void *ret = realloc(ptr, size);
 	if (!ret)
@@ -195,4 +195,12 @@ static inline void *xrealloc(void *ptr, int size)
 	return ret;
 }
 
+static inline void *xcalloc(size_t nmemb, size_t size)
+{
+	void *ret = calloc(nmemb, size);
+	if (!ret)
+		die("Out of memory, calloc failed");
+	return ret;
+}
+
 #endif /* CACHE_H */