[VectorCombine] Remove redundant checks (NFC).

The removed conditions are already checked by the if above.

Fixes #53761.

Author: fhahn

llvm/lib/Transforms/Vectorize/VectorCombine.cpp

@@ -1019,12 +1019,8 @@ bool VectorCombine::scalarizeLoadExtract(Instruction &I) {
           return false;
         NumInstChecked++;
       }
-    }
-
-    if (!LastCheckedInst)
-      LastCheckedInst = UI;
-    else if (LastCheckedInst->comesBefore(UI))
       LastCheckedInst = UI;
+    }
 
     auto ScalarIdx = canScalarizeAccess(FixedVT, UI->getOperand(1), &I, AC, DT);
     if (!ScalarIdx.isSafe()) {