boot_id is already passed by value, and hence copied.
Since we don't apply const to function parameters
that are copied anywhere else, let's drop the const
here as well for consistency.
int sd_journal_test_cursor(sd_journal *j, const char *cursor);
int sd_journal_get_cutoff_realtime_usec(sd_journal *j, uint64_t *from, uint64_t *to);
-int sd_journal_get_cutoff_monotonic_usec(sd_journal *j, const sd_id128_t boot_id, uint64_t *from, uint64_t *to);
+int sd_journal_get_cutoff_monotonic_usec(sd_journal *j, sd_id128_t boot_id, uint64_t *from, uint64_t *to);
int sd_journal_get_usage(sd_journal *j, uint64_t *ret_bytes);