drivers/mmc/mv_sdhci.c: Fix build warning

Fix:
mv_sdhci.c: In function 'mv_sdh_init':
mv_sdhci.c:47:22: warning: the comparison will always
evaluate as 'true' for the address of 'mv_sdhci_writeb'
will never be NULL [-Waddress]

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Lei Wen <leiwen@marvell.com>
Cc: Andy Fleming <afleming@freescale.com>
Acked-by: Lei Wen <leiwen@marvell.com>
1 file changed