Fix clone with commit-msg hook when project name contains '/'

Cloning a project 'foo/bar' with

  git clone ssh://<user>@<host>:29418/foo/bar

clones the project into a 'bar' folder.

This means that the commit-msg hook needs to be copied into
'bar/.git/hooks/', but so far the command tried to copy it into
'foo/bar/.git/hooks/' which failed since the folder didn't exist.

Change-Id: I2838a810682054dc1a585630480db8110bf71abc
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>