coccinelle: make use of DIV_ROUND_UP() wherever appropriate

Let's use our macros where we can

src/basic/calendarspec.c

@@ -1169,7 +1169,7 @@ static int find_matching_component(const CalendarSpec *spec, const CalendarCompo
                 } else if (c->repeat > 0) {
                         int k;
 
-                        k = start + c->repeat * ((*val - start + c->repeat - 1) / c->repeat);
+                        k = start + c->repeat * DIV_ROUND_UP(*val - start, c->repeat);
 
                         if ((!d_set || k < d) && (stop < 0 || k <= stop)) {
                                 d = k;

src/basic/exec-util.c

@@ -116,7 +116,7 @@ static int do_execute(
          * default action terminating the process, and turn on alarm(). */
 
         if (timeout != USEC_INFINITY)
-                alarm((timeout + USEC_PER_SEC - 1) / USEC_PER_SEC);
+                alarm(DIV_ROUND_UP(timeout, USEC_PER_SEC));
 
         STRV_FOREACH(path, paths) {
                 _cleanup_free_ char *t = NULL;

src/basic/hexdecoct.c

@@ -583,7 +583,7 @@ static int base64_append_width(
         if (len <= 0)
                 return len;
 
-        lines = (len + width - 1) / width;
+        lines = DIV_ROUND_UP(len, width);
 
         slen = strlen_ptr(sep);
         t = realloc(*prefix, plen + 1 + slen + (indent + width + 1) * lines);