tree-wide: use newa() rather than alloca() where we can

src/basic/calendarspec.c

@@ -104,7 +104,7 @@ static void normalize_chain(CalendarComponent **c) {
         if (n <= 1)
                 return;
 
-        j = b = alloca(sizeof(CalendarComponent*) * n);
+        j = b = newa(CalendarComponent*, n);
         for (i = *c; i; i = i->next)
                 *(j++) = i;
 

src/basic/process-util.c

@@ -1433,7 +1433,7 @@ int fork_agent(const char *name, const int except[], size_t n_except, pid_t *ret
         va_end(ap);
 
         /* Allocate strv */
-        l = alloca(sizeof(char *) * (n + 1));
+        l = newa(char*, n + 1);
 
         /* Fill in arguments */
         va_start(ap, path);