mlxsw: core_thermal: Remove unnecessary check

mlxsw: core_thermal: Remove unnecessary check

mlxsw_thermal_modules_init() allocates an array of modules and then
calls mlxsw_thermal_module_init() to initialize each entry in the array.
It is therefore impossible for mlxsw_thermal_module_init() to encounter
an entry that is already initialized and has its 'parent' pointer set.

Remove the unnecessary check.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>