staging: et131x: Remove duplicate code for fbr[0, 1]

Several places in et131x.c code is duplicated for fbr[0] and fbr[1].
Remove the duplicate lines and use loops to run over both indicies.
Signed-off-by: Mark Einon <mark.einon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>