Don't corrupt logout entries in utmp files.

An older version of the code used a structure on the stack, instead of a
pointer to the structure. It looks like I didn't adjust the parameters
of the write(2) call, causing the first four/eight bytes of the entry to
be corrupted, instead of writing the entire entry to disk.

lib/libulog/ulog_pututxline.c

@@ -126,7 +126,7 @@ ulog_write_utmp_slow(const struct futmp *ut)
 		    strncmp(utf.ut_line, ut->ut_line, sizeof utf.ut_line) != 0)
 			continue;
 		lseek(fd, -(off_t)sizeof utf, SEEK_CUR);
-		write(fd, &ut, sizeof ut);
+		write(fd, ut, sizeof *ut);
 		found = 1;
 	}
 	close(fd);