bug in mmul of vector and matrix fixed

Currently, reshaping of matrices does not work properly for NDArray. Example:
```Clojure
user=> (def Y (matrix [1 0 0 0 0]))
#'user/Y
user=> (def P (matrix [[0 2 0 0 0 0 0] [1 0 0 0 0 0 0] [0 0 0 0 0 0 0] [0 0 0 0 0 0 0] [0 0 0 0 0 0 0]]))
#'user/P
user=> (m/shape Y)
[5]
user=> (m/shape P)
[5 7]
user=> (m/mmul Y P)
#<NDArray [0.0 2.0 0.0 0.0 0.0]>
user=> (m/shape (m/mmul Y P))
[5]
```

After applying PR:
```Clojure
user=> (def Y (matrix [1 0 0 0 0]))
#'user/Y
user=> (def P (matrix [[0 2 0 0 0 0 0] [1 0 0 0 0 0 0] [0 0 0 0 0 0 0] [0 0 0 0 0 0 0] [0 0 0 0 0 0 0]]))
#'user/P
user=> (m/shape Y)
[5]
user=> (m/shape P)
[5 7]
user=> (m/mmul Y P)
#<NDArray [0.0 2.0 0.0 0.0 0.0 0.0 0.0]>
user=> (m/shape (m/mmul Y P))
[7]
```