[NFC] Fix typo in comment.

[cherry]

LGTM.

llvm/lib/CodeGen/StackColoring.cpp

bool StackColoring::runOnMachineFunction(MachineFunction &Func) {
   // Do not bother looking at empty intervals.
   for (unsigned I = 0; I < NumSlots; ++I) {
     if (Intervals[SortedSlots[I]]->empty())
       SortedSlots[I] = -1;
   }
 
   // This is a simple greedy algorithm for merging allocas. First, sort the
   // slots, placing the largest slots first. Next, perform an n^2 scan and look
-  // for disjoint slots. When you find disjoint slots, merge the samller one
+  // for disjoint slots. When you find disjoint slots, merge the smaller one
   // into the bigger one and update the live interval. Remove the small alloca
   // and continue.
 
   // Sort the slots according to their size. Place unused slots at the end.
   // Use stable sort to guarantee deterministic code generation.
   llvm::stable_sort(SortedSlots, [this](int LHS, int RHS) {
     // We use -1 to denote a uninteresting slot. Place these slots at the end.
     if (LHS == -1)