kiss: fix possible KISS_ROOT usage

If the user defines KISS_ROOT to / or anything that ends
with '/', some functions will not work as intended (like fixdeps).
This removes the '/' at the very end, if it exists.

Signed-off-by: Dylan Araps <dylan.araps@gmail.com>

kiss

@@ -1325,6 +1325,10 @@ main() {
     # This is used enough to warrant a place here.
     uid=$(id -u)
 
+    # Make sure that the KISS_ROOT doesn't end with a '/'. This might
+    # break some operations.
+    KISS_ROOT=${KISS_ROOT%/}
+
     # This allows for automatic setup of a KISS chroot and will
     # do nothing on a normal system.
     mkdir -p "${sys_db:=$KISS_ROOT/$pkg_db}" 2>/dev/null ||: