[PATCH] bcm43xx-softmac: check returned value from pci_enable_device

Linus's tree now has a configuration option that prints a warning whenever
the returned value of any routine is ignored. This patch fixes the only such
warning for bcm43xx.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>