staging: emxx_udc: use min helper macro for variable comparison

Simplify code by using min helper macros in place of lengthy if/else
block oriented logical evaluation and value assignment. This issue is
identified by coccicheck using the minmax.cocci file.

Signed-off-by: Deepak R Varma <drv@mailo.com>
Link: https://lore.kernel.org/r/Y2eKxoUWtbPY/88b@qemulion


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>