staging: rtl8192u: limit line size in r819xU_phy.c

This patch limits the line size below 80 characters,
when possible without producing new checkpatch errors.

This is done by adjusting identation, replacing hardcoded
function names in messages with __func__, merging some
trailing comments with the header comments when they both
refer to the same line and removing some unnecessary
parenthesis.

Also, changes slightly some RT_TRACE messages to make
them shorter without altering their content.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>