libopkg: fix double-free crash on recursive package removal

libopkg: fix double-free crash on recursive package removal

The opkg_remove_dependent_pkgs() function will trigger a pkg_vec_free() and
break the loop when an error is returned by opkg_remove_pkg().

Since the vector is freed anyway after the loop, a double free occurs,
leading to a segmentation fault.

This situation commonly happens when recursively deleting packages in
conjunction with --autoremove where dependent packages might already have
been removed by previous iterations.

Simply break the loop without prematurely freeing the vector to fix this.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>