misc: cxl: flash: Remove unused variable 'drc_index'

misc: cxl: flash: Remove unused variable 'drc_index'

Keeping the pointer increment though.

Fixes the following W=1 kernel build warning:

 drivers/misc/cxl/flash.c: In function ‘update_devicetree’:
 drivers/misc/cxl/flash.c:178:16: warning: variable ‘drc_index’ set but not used [-Wunused-but-set-variable]
 178 | __be32 *data, drc_index, phandle;
 | ^~~~~~~~~

Cc: Frederic Barrat <fbarrat@linux.ibm.com>
Cc: Andrew Donnellan <ajd@linux.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200709065651.GY3500@dell
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>