mmc: sdhci-s3c: Fix return value in sdhci_s3c_suspend/resume()

Signed-off-by: Wonil Choi <wonil22.choi@samsung.com>
Signed-off-by: Minho Ban <mhban@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>