Fix some comment typos.

llvm-svn: 244402
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 734056d..d39b49f 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -519,7 +519,7 @@
           if (isa<OverflowingBinaryOperator>(Op1))
             HasNSW &= Op1->hasNoSignedWrap();
 
-        // We can propogate 'nsw' if we know that
+        // We can propagate 'nsw' if we know that
         //  %Y = mul nsw i16 %X, C
         //  %Z = add nsw i16 %Y, %X
         // =>