util-lib: split out allocation calls into alloc-util.[ch]

src/basic/socket-util.c

@@ -30,6 +30,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include "alloc-util.h"
 #include "fd-util.h"
 #include "fileio.h"
 #include "formats-util.h"