[VirtualBox-kmod/el7] (6 commits) ...Update VBox to 5.2.20

Summary of changes: f776e45... - Rebuilt for https://fedoraproject.org/wiki/Fedora_29_Mass (*) 6d1bc53... Update to 5.2.18 (*) 0e55d69... Fixes for kernel 4.18 (*) fd77029... Update master source, fixes kernel 4.18 >=f28 (rfbz#5017) (*) ad27d26... Update VBox to 5.2.20 (*) 7b3d593... Update VBox to 5.2.20 (*) (*) This commit already existed in another branch; no separate mail sent