Some unusual modes required re-parsing the value. Instead of assigning the
re-parsed value to *floatval, it was reassigned directly to *analog->data;
however, analog->data is not initialized at this point, causing a segfault.
This situation was created when moving the radioshack-dmm code to serial-dmm,
with the segfault not being observed at that time.
Do not write directly to analog->data, but instead use the intermediate
variable rawval.
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>