bootzip: Fix erroneous zip structure creation
bootzip: Fix erroneous zip structure creation

 * Introduced in "bootzip: Improve function style...",
    the zip creation was broken due to not using relative
    paths upon zip creation and additions

 * Also delete leftover .unsigned.zip file

Change-Id: I1d0e2a326b44383dccfd6ceded2a4aa00d870f24
Signed-off-by: Adrian DC <01fb3892f39957945220431e7409156544d2f041@gmail.com>

AdrianDC/android_development_shell_tools,AdrianDC/android_development_shell_tools