basic: rename util.h to logarithm.h

util.h is now about logarithms only, so we can rename it. Many files included
util.h for no apparent reason… Those includes are dropped.

src/cryptsetup/cryptsetup-generator.c

@@ -23,7 +23,6 @@
 #include "string-util.h"
 #include "strv.h"
 #include "unit-name.h"
-#include "util.h"
 
 typedef struct crypto_device {
         char *uuid;