This corrects what appear to be typos, making the code consistent with
itself, and allowing meaningful prefixes to be displayed with the errors in
question.

Before:
 (null): failed to initialize MDIO
 (null): Cannot allocate desc base address table (size 176 bytes)

After:
ravb e6800000.ethernet: failed to initialize MDIO
ravb e6800000.ethernet: Cannot allocate desc base address table (size 176 bytes)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>