staging: rtl8192e: Replace min with min_t

This patch replaces min with min_t and eliminates the
following warnings found by checkpatch.pl:

WARNING: min() should probably be min_t

Signed-off-by: Darshana Padmadas <darshanapadmadas@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>