vfs: remove the dead code in namei()

When control flow reaches at the bottom inner loop in namei(), the pointer p
will point to either a '\0' or a '/' character because of the upper inner loop
break condition:


        for (i = 0; i < PATH_MAX; i++) {
            if (*p == '\0' || *p == '/') {
                break;
            }
            name[i] = *p++;
        }

So the "while" loop will never be executed and we can eliminate it as dead
code.

Reviewed-by: Raphael S. Carvalho <raphaelsc@cloudius-systems.com>
Signed-off-by: Zhi Yong Wu <zwu.kernel@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>