Changes

linux+lstopo: disable memory binding in the linux backend on Android

get_mempolicy() crashes on some Android (e.g. android10/aarch64/3.18)
and in some versions of the emulator in Android Studio.
It's used by lstopo for getting the current binding, but the Android
app doesn't need this anyway.

Disable the Linux membind hooks instead of just disabling get_*bind()
calls in lstopo.

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>

lstopo/draw: cleanup the drawing of legend text lines

Only generate the lines once during prepare and reuse them during draw.
And cleanup random minor things.

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>

doc: minor fixes

Signed-off-by: Bert Wesarg <bert.wesarg@tu-dresden.de>