Backport to 1.20 "modesetting: Fix front_bo leak at drmmode_xf86crtc_resize on XRandR rotation"
Since the introduction of "modesetting: Remove unnecessary fb addition from drmmode_xf86crtc_resize" the fb_id isn't initialited at drmmode_xf86crtc_resize.
Rotate operation of XRandR uses rotate_bo. So in this case the fb_id associated to the front_bo is not initialized at drmmode_set_mode_major. So fd_id remains 0.
As every call to drmmode_xf86crtc_resize allocates a new front_bo we should destroy unconditionally the old_front_bo if operation success. So we free the allocated GBM handles.
This avoids crashing xserver with a OOM in the RPI4 1Gb at 4k resolution after 3 series xrandr rotations from normal to left and vice versa reported at https://github.com/raspberrypi/firmware/issues/1345
Signed-off-by: Jose Maria Casanova Crespo firstname.lastname@example.org Reviewed-by: Keith Packard email@example.com Closes: #1024 (closed) Fixes: 87745321 "modesetting: Remove unnecessary fb addition from drmmode_xf86crtc_resize" (cherry picked from commit 73480f17)