fix CLEAN_PRJ variable to same name (remove CLEANPRJ)

protect variables and paths with quotes

Will fix : ./yoctoTizenUpdateSource: line 240: [: =: unary operator expected

Change-Id: Ic15f14bc2800b4d812002f24afa677a5eaa4a2cc
Signed-off-by: Philippe Coval <philippe.coval@open.eurogiciel.org>