build: remove pointless condition

$(STRIP) always expands to something, because it is one of the commands
in the BRIEF list. This renders the condition pointless.

Signed-off-by: Ingo Brückl <ib@wupperonline.de>
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
tree-test: Don't return restricted exit codes

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
base64-test: Remove posibility of returning restrcted exit codes

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
dct-test: Remove possibility of returning a restricted exit code

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
fft-test: Remove possibility of returning restricted exit code

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
lavd/x11grab: Support AV_PIX_FMT_PAL8.

Fixes ticket #3068.