revwalk: remove one useless layer of functions

We don't currently need to have anything that's different between `get_revision`
and `get_one_revision` so let's just remove the inner function and make the code
more straightforward.

src/revwalk.c

@@ -453,12 +453,11 @@ static int limit_list(git_commit_list **out, git_revwalk *walk, git_commit_list
 	return 0;
 }
 
-static int get_one_revision(git_commit_list_node **out, git_revwalk *walk, git_commit_list **list)
+static int get_revision(git_commit_list_node **out, git_revwalk *walk, git_commit_list **list)
 {
 	int error;
 	git_commit_list_node *commit;
 
-	while(true) {
   commit = git_commit_list_pop(list);
   if (!commit) {
     giterr_clear();
@@ -476,20 +475,6 @@ static int get_one_revision(git_commit_list_node **out, git_revwalk *walk, git_c
 
   *out = commit;
   return 0;
-	}
-}
-
-static int get_revision(git_commit_list_node **out, git_revwalk *walk, git_commit_list **list)
-{
-	int error;
-	git_commit_list_node *commit;
-
-	if ((error = get_one_revision(&commit, walk, list)) < 0)
-		return error;
-
-	/* Here is where we would handle boundary commits if we implement that */
-	*out = commit;
-	return 0;
 }
 
 static int sort_in_topological_order(git_commit_list **out, git_revwalk *walk, git_commit_list *list)