usb: dwc2: Use kmem_cache_free()

Here, free memory is allocated using kmem_cache_zalloc.  So, use
kmem_cache_free instead of kfree.

This is done using Coccinelle and semantic patch used
is as follows:

//<smpl>
@@
expression x,E,c;
@@
 x =
\(kmem_cache_alloc\|kmem_cache_zalloc\|kmem_cache_alloc_node\)(c,...)
 ... when != x = E
     when != &x
?-kfree(x)
+kmem_cache_free(c,x)
//</smpl>

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>