Fixed problem with multiple mount/unmount for different devices.
Additional check for structure length included into the code.
Remove useless spaces.
Added initialization for reserved memory.
This change allows readonly FATFS to be mounted without wear levelling
support. This will provide the customers a simple way to mount FATFS images
generated on host and flashed onto the chip during factory provisioning.
Since NVS encryption is not supported yet and NVS entry size is limited,
the change will provide an easy alternative for securing the provisioning data
by just marking FATFS parition as encrypted.
- fix null pointer dereference in VFS when VFS implementations are added
and removed in different order
- vfs_fat_sdmmc, vfs_fat_spiflash: pass correct drive to mkfs
(previously it would always do mkfs in the first drive)
- add test case
