drop __restrict some more, to please old compilers

Avoid the __restrict keyword in roken to appease older compilers.

lib/roken/strtoull.c

@@ -53,7 +53,7 @@
  * alphabets and digits are each contiguous.
  */
 ROKEN_LIB_FUNCTION unsigned long long ROKEN_LIB_CALL
-strtoull(const char * __restrict nptr, char ** __restrict endptr, int base)
+strtoull(const char * nptr, char ** endptr, int base)
 {
     const char *s;
     unsigned long long acc;