Consistently use new_cap in signatures of reserve_total
diff --git a/src/rust_vec.rs b/src/rust_vec.rs
index e66519f..b2df5f3 100644
--- a/src/rust_vec.rs
+++ b/src/rust_vec.rs
@@ -56,11 +56,11 @@
         self.as_vec().as_ptr()
     }
 
-    pub fn reserve_total(&mut self, cap: usize) {
+    pub fn reserve_total(&mut self, new_cap: usize) {
         let vec = self.as_mut_vec();
         let len = vec.len();
-        if cap > len {
-            vec.reserve(cap - len);
+        if new_cap > len {
+            vec.reserve(new_cap - len);
         }
     }