Local backend: Align the buffers when reading/writing multiple attrs
Local backend: Align the buffers when reading/writing multiple attrs

Otherwise, SIGBUS will occur on some architectures when reading or
writing to an un-aligned address (and it's a very bad idea to do so in
general).

Signed-off-by: Paul Cercueil <73d292422978d45c9eeef455bb1b24a0db453722@analog.com>

Sunderfield/libiio,sensarliar/libiio,sensarliar/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio,gburca/libiio,Sunderfield/libiio,gburca/libiio,analogdevicesinc/libiio,gburca/libiio,analogdevicesinc/libiio,sensarliar/libiio,Sunderfield/libiio