Remove definition of PRI?64 in util.h

This was a bad idea. This can't be solved with macros as any
other library that includes inttypes.h will get in the way.

The parent commit has removed all usages from the source, this commit
removes the definition.

src/util.h

@@ -44,15 +44,10 @@ static const int64_t CENT = 1000000;
 #define UEND(a)             ((unsigned char*)&((&(a))[1]))
 #define ARRAYLEN(array)     (sizeof(array)/sizeof((array)[0]))
 
-/* Format characters for (s)size_t, ptrdiff_t, uint64_t.
+/* Format characters for (s)size_t, ptrdiff_t.
  *
- * As the tinyformat-based formatting system is type-safe, no special format
- * characters are really needed to specify sizes. Tinyformat can support
- * (ignores) the C99 prefixes such as "ll" but chokes on MSVC's inttypes
- * defines prefixes such as "I64X".  So don't include inttypes.h and define our
- * own for compatibility.
- * If you get a warning here about a redefine of PRI?64, make sure that
- * inttypes.h is not included.
+ * Define these as empty as the tinyformat-based formatting system is
+ * type-safe, no special format characters are needed to specify sizes.
  */
 #define PRIszx    "x"
 #define PRIszu    "u"
@@ -60,9 +55,6 @@ static const int64_t CENT = 1000000;
 #define PRIpdx    "x"
 #define PRIpdu    "u"
 #define PRIpdd    "d"
-#define PRIx64    "x"
-#define PRIu64    "u"
-#define PRId64    "d"
 
 // This is needed because the foreach macro can't get over the comma in pair<t1, t2>
 #define PAIRTYPE(t1, t2)    std::pair<t1, t2>