Fix wrong comments in groupmanager.h for doxygen

Fix wrong comments in groupmanager.h for doxygen

A name of parameter in a function prototype should be matched with
a name following *@param* keyword for doxygen.

Change-Id: I892de77f163bbf5781735fce897ee11f850718b5
Signed-off-by: Jihun Ha <jihun.ha@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/3483
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Madan Lanka <lanka.madan@samsung.com>
(cherry picked from commit 9f0a4365d7303da64b6ea7cad9851ff0b6fc6475)
Reviewed-on: https://gerrit.iotivity.org/gerrit/3537