[X86] X86MCInstLower.cpp - fix spelling mistake

Author: RKSimon

llvm/lib/Target/X86/X86MCInstLower.cpp

@@ -1501,7 +1501,7 @@ static void printConstant(const APInt &Val, raw_ostream &CS) {
 
 static void printConstant(const APFloat &Flt, raw_ostream &CS) {
   SmallString<32> Str;
-  // Force scientific notation to distinquish from integers.
+  // Force scientific notation to distinguish from integers.
   Flt.toString(Str, 0, 0);
   CS << Str;
 }