[PATCH] gianfar: fix compile warning

[Jeff Garzik]

Grant Likely wrote:
> From: Grant Likely <grant.likely at secretlab.ca>
> 
> Eliminate an uninitialized variable warning.  The code is correct, but
> a pointer to the automatic variable 'addr' is passed to dma_alloc_coherent.
> Since addr has never been initialized, and the compiler doesn't know
> what dma_alloc_coherent will do with it, it complains.
> 
> Signed-off-by: Grant Likely <grant.likely at secretlab.ca>
> ---
> 
> Jeff, this one should go in for 2.6.24

applied #upstream-fixes