Fix logic and debug output in server-side observe handler
Fix logic and debug output in server-side observe handler

* Minor fixup of logic and debug output in ...remove_observer functions.

Change-Id: I75567603b104b80e4d07a621d8d8931c004b9d63
Signed-off-by: Kishen Maloor <c62ddea3cd661a9268bff15f07fc2229cdc9ac02@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/11181
Reviewed-by: Thiago Macieira <0ed1648d92ca0373297a182b1dba1b974ad10d88@intel.com>
Tested-by: Thiago Macieira <0ed1648d92ca0373297a182b1dba1b974ad10d88@intel.com>

iotivity/iotivity-constrained,iotivity/iotivity-constrained,iotivity/iotivity-constrained,iotivity/iotivity-constrained