staging: rtl8192e: Fix LONG_LINE warnings

Fix most of simple LONG_LINE warnings. None of the changes should affect
behaviour of code, so several modifications are included in this patch:
- Code is reindented where needed
- Local variable names are compacted (priv -> p)
- Unnecessary casts are removed
- Nested ifs are replaced with logical and
- a = b = c = d expressions are split
- Replace if/then series with clamp_t()
- Removed unneeded scopes

Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>