[ETH] forcdeth: increase max_interrupt_work

[Joe Korty <joe.korty@ccur.com>]

Forcedeth: increase max_interrupt_work

This eliminates the following often-generated warning from
my 64 bit Opteron SMP test stand:

	eth0: too many iterations (6) in nv_nic_irq

According to the web, the problem is that the forcedeth
driver has a too-low value for max_interrupt_work.
Grepping the kernel I see that forcedeth has the second
lowest value of all ethernet drivers (ie, 6).  Most are
in the 20-40 range.  So this patch increases this a bit,
from 6 to 15 (at 15 forcedeth becomes the driver with
third-lowest max_interrupt_work value).

My test stand, which used to print out the above warnings
repetitively whenever it was under heavy net load, no
longer does so.

Signed-off-by: Joe Korty <joe.korty@ccur.com>

Index: 2.6.27-rc4-git4/drivers/net/forcedeth.c
===================================================================
--- 2.6.27-rc4-git4.orig/drivers/net/forcedeth.c	2008-08-27 09:49:13.000000000 -0400
+++ 2.6.27-rc4-git4/drivers/net/forcedeth.c	2008-08-27 10:02:40.000000000 -0400
@@ -818,7 +818,7 @@
  * Maximum number of loops until we assume that a bit in the irq mask
  * is stuck. Overridable with module param.
  */
-static int max_interrupt_work = 5;
+static int max_interrupt_work = 15;
 
 /*
  * Optimization can be either throuput mode or cpu mode