drivers/staging/rts5139:xd.c: Fix line over 80 characters.

Fix checkpatch.pl issues with line over 80 characters in xd.c

Signed-off-by: Aybuke Ozdemir <aybuke.147@gmail.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>