buildroot

scancpan: adjust package name

underscore is not allowed in BR package name.
this problem was found with the Perl module DB_File
which must give the BR package perl-db-file.

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>