staging: rtl8192u: r8192U_core: fix quoted string split across lines code style issue

Quoted strings should not be split to help text grep in the source.
All quoted strings that were split have thus been merged to one unique
quoted string each to follow the code style.

Signed-off-by: Raphaël Beamonte <raphael.beamonte@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>