fs/smartfs: fix read_dir error
fs/smartfs: fix read_dir error

Current sector should have a space for next entry size. If not, we
should move to next sector.

this patch from nuttx

commit a2798154348cc5fe9fcdc73ecd64b32ea054486f
Author: EunBong Song <eunb.song@samsung.com>

Change-Id: Ieca38d7074c93f88e1285783bed12069ec999d35
Signed-off-by: Heuisam Kwag <2145cbb01e90577cd4983eccc3b7d9a9dfba6875@samsung.com>

JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT