Remove loops witch never loops fixes rust-ndarray#642

Author: alex179ohm

src/dimension/dimension_trait.rs

@@ -130,9 +130,8 @@ pub trait Dimension:
         if self.slice().iter().all(|&d| d != 0) {
             let mut it = strides.slice_mut().iter_mut().rev();
             // Set first element to 1
-            while let Some(rs) = it.next() {
+            if let Some(rs) = it.next() {
                 *rs = 1;
-                break;
             }
             let mut cum_prod = 1;
             for (rs, dim) in it.zip(self.slice().iter().rev()) {
@@ -156,9 +155,8 @@ pub trait Dimension:
         if self.slice().iter().all(|&d| d != 0) {
             let mut it = strides.slice_mut().iter_mut();
             // Set first element to 1
-            while let Some(rs) = it.next() {
+            if let Some(rs) = it.next() {
                 *rs = 1;
-                break;
             }
             let mut cum_prod = 1;
             for (rs, dim) in it.zip(self.slice()) {