RT-Thread/rt-thread — pull request #321 by yuht (2014-08-25 23:40:54+00:00)
Title: Complate SD optration rt_err_t rt_sdcard_control()

Complate SD optration "rt_err_t rt_sdcard_control()" at RT_DEVICE_CTRL_BLK_GETGEOME for GETGEOME.
else Initialization was failed.
完善函数"rt_err_t rt_sdcard_control()"，当调用RT_DEVICE_CTRL_BLK_GETGEOME时，如果args返回空，会初始化失败。