Add missing break statement in PPCISelLowering

As it turns out, not a problem in practice, but it should be there.

llvm-svn: 190720

llvm/lib/Target/PowerPC/PPCISelLowering.cpp

@@ -7321,6 +7321,8 @@ SDValue PPCTargetLowering::PerformDAGCombine(SDNode *N,
         }
       }
     }
+
+    break;
   case ISD::BSWAP:
     // Turn BSWAP (LOAD) -> lhbrx/lwbrx.
     if (ISD::isNON_EXTLoad(N->getOperand(0).getNode()) &&