[X86ISelLowering] Fixed typo in assert. NFCI.

Author: davidbolvansky

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -21722,7 +21722,7 @@ static SDValue LowerSIGN_EXTEND(SDValue Op, const X86Subtarget &Subtarget,
     return LowerSIGN_EXTEND_Mask(Op, Subtarget, DAG);
 
   assert(VT.isVector() && InVT.isVector() && "Expected vector type");
-  assert(VT.getVectorNumElements() == VT.getVectorNumElements() &&
+  assert(VT.getVectorNumElements() == InVT.getVectorNumElements() &&
          "Expected same number of elements");
   assert((VT.getVectorElementType() == MVT::i16 ||
           VT.getVectorElementType() == MVT::i32 ||