envy24control: fix memory access errors in profiles

envy24control: fix memory access errors in profiles

Fix two memory errors in the profiles parser: an invalid read and a
"source and destination overlap in strncpy" warning.

When the profiles page is initialized it fetches the profile names from
the profiles file. When a profile wasn't defined in the file, the parser
made invalid reads outside the buffer.

Closes: https://github.com/alsa-project/alsa-tools/pull/34
Signed-off-by: Andreas Persson <andreasp56@outlook.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>