MdeModulePkg/EbcDxe: Fix spelling mistake

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2360



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