Handle or voidify all calls to close_all_fds()

In activate, it is important that we close the fds. In other cases, meh.

src/activate/activate.c

@@ -74,7 +74,9 @@ static int open_sockets(int *epoll_fd, bool accept) {
                         except[fd] = fd;
 
                 log_close();
-                close_all_fds(except, 3 + n);
+                r = close_all_fds(except, 3 + n);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to close all file descriptors: %m");
         }
 
         /** Note: we leak some fd's on error here. I doesn't matter

src/basic/process-util.c

@@ -1001,7 +1001,7 @@ _noreturn_ void freeze(void) {
         log_close();
 
         /* Make sure nobody waits for us on a socket anymore */
-        close_all_fds(NULL, 0);
+        (void) close_all_fds(NULL, 0);
 
         sync();
 

src/nspawn/nspawn-setuid.c

@@ -43,7 +43,7 @@ static int spawn_getent(const char *database, const char *key, pid_t *rpid) {
                 if (rearrange_stdio(-1, pipe_fds[1], -1) < 0)
                         _exit(EXIT_FAILURE);
 
-                close_all_fds(NULL, 0);
+                (void) close_all_fds(NULL, 0);
 
                 (void) rlimit_nofile_safe();
 

src/nspawn/nspawn-stub-pid1.c

@@ -67,7 +67,7 @@ int stub_pid1(sd_id128_t uuid) {
         reset_all_signal_handlers();
 
         log_close();
-        close_all_fds(NULL, 0);
+        (void) close_all_fds(NULL, 0);
         log_open();
 
         /* Flush out /proc/self/environ, so that we don't leak the environment from the host into the container. Also,