print that there are no files when there are no files

[soldair]

also mentioned in #1

when you have zero files it's not clear if the program just exited or you have an empty flash.
it would be nice to have a "no files found" message

[AndiDittrich]

i've added the feature to the current master/dev branch bf42203
the output will look like as follows:

3 Files

[NodeMCU-Tool] Connected
[NodeMCU] Version: 0.9.5 | ChipID: 0xd1aa | FlashID: 0x1640e0
[NodeMCU] Free Disk Space: 3330 KB | Total: 3346 KB | 3 Files
[NodeMCU] Files stored into Flash (SPIFFS)
          |- helloworld.lc (492 Bytes)
          |- README.md (13820 Bytes)
          |- helloworld.lua (382 Bytes)

No Files

andi@sapphire:~/Development/IoT/NodeMCU-Tool$ ./bin/nodemcu-tool.js fsinfo
[NodeMCU-Tool] Connected
[NodeMCU] Version: 0.9.5 | ChipID: 0xd1aa | FlashID: 0x1640e0
[NodeMCU] Free Disk Space: 3346 KB | Total: 3346 KB | 0 Files
[NodeMCU] No Files found - do you have created the file-system ?

btw. you should take care of the exit codes - in case any unpredictable errors happened, a exit code > 0 will returned