staging: wfx: cleanup long lines in data_tx.c

Break lines with length over 80 characters to
conform to the linux coding style and refactor
wherever necessary.

Reviewed-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Signed-off-by: Suraj Upadhyay <usuraj35@gmail.com>
Link: https://lore.kernel.org/r/20200425113234.GA14492@blackclown


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>