Removed duplicate switch case in OCDoResource.

Removed duplicate switch case in OCDoResource.

There were two separate switch statements for validation and converting
to CA method. Moved it to one.
Also improved logging, variable names and vertical spacing in some
sections.

Change-Id: Ic68253dd23e5da15d469951293fc4173a13f7afd
Signed-off-by: Mandeep Shetty <mandeep.shetty@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/1045
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Doug Hudson <douglas.hudson@intel.com>
Reviewed-by: Erich Keane <erich.keane@intel.com>