staging: pi433: fix CamelCase for preambleLength variable

Fixes checkpatch warning:

  CHECK: Avoid CamelCase: <preambleLength>

Signed-off-by: Valentin Vidic <Valentin.Vidic@CARNet.hr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2 files changed