Fix messages of command: rm

Right now, rm command doesn't differentiate between a file and a directory.
For example, on deleting a directory, it says "file deleted". This patch
fixes the issue.

Signed-off-by: Nehal J Wani <nehaljw.kkd1@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>