e1000e: make a function static

This patch makes the needlessly global reg_pattern_test_array() static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>