various fixes (#49)

* libs: libc: math: Fix tanh() math functions
* drivers: mtd: smart: Fix trivial debug message in smartfs
* binfmt: libelf: Fix fd not closed on error
* binfmt: Fix stack memory leak on error
* fs: romfs: Fix private data not free on error
* sched: group: Fix reference after free memory
* sched: clock: Fix clock sync

Fix clock sync when CONFIG_RTC_HIRES is enabled

binfmt/binfmt_execmodule.c

@@ -186,6 +186,7 @@ int exec_module(FAR const struct binary_s *binp)
     {
       ret = -get_errno();
       berr("task_init() failed: %d\n", ret);
+      kumm_free(stack);
       goto errout_with_addrenv;
     }