We can safely cast the data in a GArray to gpointer first, and then
to the pointer type we require.
xmm/mm-shared-xmm.c: In function 'validate_and_build_command_set_current_bands':
xmm/mm-shared-xmm.c:512:45: error: cast increases required alignment of target type [-Werror=cast-align]
str = mm_common_build_bands_string ((const MMModemBand *)unapplied_bands->data, unapplied_bands->len);
^