[Gardening] Fixed typo.

Author: nate-chandler

lib/SILGen/SILGenDecl.cpp

@@ -808,7 +808,7 @@ class LetValueInitialization : public Initialization {
     // If we have a no implicit copy lexical, emit the instruction stream so
     // that the move checker knows to check this variable.
     if (vd->isNoImplicitCopy()) {
-      value = SGF.B.createMoveValue(PrologueLoc, value, /*IisLexical*/ true);
+      value = SGF.B.createMoveValue(PrologueLoc, value, /*isLexical*/ true);
       value = SGF.B.createOwnedCopyableToMoveOnlyWrapperValue(PrologueLoc, value);
       return SGF.B.createMarkMustCheckInst(
           PrologueLoc, value,