[NFC][llvm][M68k] Inclusive language: reword comment

Rewording the comment to avoid the use of blacklist.

Author: ZarkoT

llvm/lib/Target/M68k/M68kISelLowering.cpp

@@ -2202,7 +2202,7 @@ SDValue M68kTargetLowering::LowerSELECT(SDValue Op, SelectionDAG &DAG) const {
       Op2.getOpcode() == ISD::TRUNCATE) {
     SDValue T1 = Op1.getOperand(0), T2 = Op2.getOperand(0);
     if (T1.getValueType() == T2.getValueType() &&
-        // Blacklist CopyFromReg to avoid partial register stalls.
+        // Block CopyFromReg so partial register stalls are avoided.
         T1.getOpcode() != ISD::CopyFromReg &&
         T2.getOpcode() != ISD::CopyFromReg) {
       SDVTList VTs = DAG.getVTList(T1.getValueType(), MVT::Glue);