[fprint] Egistec S801U

[Fabian Zaremba]

Hello,

I found a repository on github containing libfprint support for the 
Egistec S801U (ID 1c7a:0801 LighTuning Technology Inc. Fingerprint Reader):
https://github.com/lielfr/Libfprint-for-Egistec-S801U

However, as this seems to be based on a 0.4.x branch I rebased this on 
the current git repo for personal use.

I was able to get this working using an additional patch against 
libfprint imgdev.c found in Bug 30287 - 
https://bugs.freedesktop.org/show_bug.cgi?id=30287 - without this patch 
the device would not accept a second scan after the first failed but 
instead loop in verify_retry_scan until timeout.

You can find my patchset against current git master (commit 35e356f6) here:
https://nf-design.eu/cloud/d/3a191bd2b2/

Some parts of it are still a bit crude, like inclusion of the driver in 
core.c or libfprint/Makefile.am. Additionally, I just took the first 
available driver id 19.

Any chance these patches could get into upstream?

Thank you,
Fabian Zaremba