ShellPkg/UefiShellAcpiViewCommandLib: Fix VS2012 build failure

Fix following build error:
UefiShellAcpiViewCommandLib\AcpiParser.c(519) :
error C2308: concatenating mismatched strings
Concatenating wide "ERROR: %a: Offset Mismatch for %s"
with narrow "CurrentOffset = %d FieldOffset = %d"

cc: Alexei Fedorov <Alexei.Fedorov@arm.com>
cc: Ruiyu Ni <ruiyu.ni@intel.com>
cc: Jaben Carsey <jaben.carsey@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Dandan Bi <dandan.bi@intel.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>