MdeModulePkg/Variable/RuntimeDxe: Fix return status from Reclaim()

MdeModulePkg/Variable/RuntimeDxe: Fix return status from Reclaim()

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2844

Update Reclaim() to return the error status from the reclaim
operation and not the status of SynchronizeRuntimeVariableCache()
that can be EFI_SUCCESS even through the status from reclaim
is an error.  Without this change, the return status from
SetVariable() can be EFI_SUCCESS even though the variable was
not actually set.  This occurs if the variable store is full
and a Reclaim() is invoked to free up space and even after all
possible space is freed, there is still not enough room for
the variable being set.  This condition should return
EFI_OUT_OF_RESOURCES.

Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>