Fix shadowed variable in faiss/impl/residual_quantizer_encode_steps.cpp

Summary:
Our upcoming compiler upgrade will require us not to have shadowed variables. Such variables have a _high_ bug rate and reduce readability, so we would like to avoid them even if the compiler was not forcing us to do so.

This codemod attempts to fix an instance of a shadowed variable. Please review with care: if it's failed the result will be a silent bug.

**What's a shadowed variable?**

Shadowed variables are variables in an inner scope with the same name as another variable in an outer scope. Having the same name for both variables might be semantically correct, but it can make the code confusing to read! It can also hide subtle bugs.

This diff fixes such an issue by renaming the variable.

 - If you approve of this diff, please use the "Accept & Ship" button :-)

Reviewed By: algoriddle

Differential Revision: D52959180

fbshipit-source-id: 90f735f65f1306c817d80c99c8a2108aee7c599a

Author: r-barnes

faiss/impl/residual_quantizer_encode_steps.cpp

@@ -292,8 +292,8 @@ void beam_search_encode_step(
                     cent_ids.data() + i * beam_size * new_beam_size;
 
             // here we could be a tad more efficient by merging sorted arrays
-            for (int i = 0; i < new_beam_size; i++) {
-                new_distances_i[i] = C::neutral();
+            for (int i_2 = 0; i_2 < new_beam_size; i_2++) {
+                new_distances_i[i_2] = C::neutral();
             }
             std::vector<int> perm(new_beam_size, -1);
             heap_addn<C>(
@@ -325,8 +325,8 @@ void beam_search_encode_step(
             const float* cent_distances_i =
                     cent_distances.data() + i * beam_size * K;
             // then we have to select the best results
-            for (int i = 0; i < new_beam_size; i++) {
-                new_distances_i[i] = C::neutral();
+            for (int i_2 = 0; i_2 < new_beam_size; i_2++) {
+                new_distances_i[i_2] = C::neutral();
             }
             std::vector<int> perm(new_beam_size, -1);
 
@@ -558,8 +558,8 @@ void beam_search_encode_step_tab(
         const float* cent_distances_i = cent_distances.data();
 
         // then we have to select the best results
-        for (int i = 0; i < new_beam_size; i++) {
-            new_distances_i[i] = C::neutral();
+        for (int i_2 = 0; i_2 < new_beam_size; i_2++) {
+            new_distances_i[i_2] = C::neutral();
         }
         std::vector<int> perm(new_beam_size, -1);