staging: et131x: Refactor nic_rx_pkts() to remove indenting

In nic_rx_pkts() some large chunks of code are indented in 'if (len)'
sections. Refactor the code to remove these indents and re-join longer
split lines.

Signed-off-by: Mark Einon <mark.einon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>