[libami] handle EINTR from select() as a non-error

EINTR is happening during suspend/resume, which was causing all of
the modules to die (and requiring a restart of amiwm to re-run all
of its modules.)

This fixes things in FreeBSD suspend/resume so, well, the modules
keep working. :)

libami/module.c

@@ -81,6 +81,13 @@ md_wait_read_fd(void)
     return (0);
   }
   if (ret < 0) {
+    /*
+     * Note: this happens during things like system suspend/resume
+     * on FreeBSD.
+     */
+    if (errno == EINTR) {
+        return (0);
+    }
     return (-1);
   }
   if (FD_ISSET(md_in_fd, &readfds)) {