usb: usb-skeleton: make comment block in line with coding style

Comment block was not in accordance with coding style.
Fixes two checkpatch warnings:
WARNING: Block comments use * on subsequent lines
WARNING: Block comments use a trailing */ on a separate line
Signed-off-by: Jacob Huisman <jacobhuisman@kernelthusiast.com>
Link: https://lore.kernel.org/r/20190815174210.580-1-jacobhuisman@kernelthusiast.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/usb-skeleton.c

@@ -35,9 +35,11 @@ MODULE_DEVICE_TABLE(usb, skel_table);
 
 /* our private defines. if this grows any larger, use your own .h file */
 #define MAX_TRANSFER		(PAGE_SIZE - 512)
-/* MAX_TRANSFER is chosen so that the VM is not stressed by
-   allocations > PAGE_SIZE and the number of packets in a page
-   is an integer 512 is the largest possible packet on EHCI */
+/*
+ * MAX_TRANSFER is chosen so that the VM is not stressed by
+ * allocations > PAGE_SIZE and the number of packets in a page
+ * is an integer 512 is the largest possible packet on EHCI
+ */
 #define WRITES_IN_FLIGHT	8
 /* arbitrarily chosen */