mmc: core: Add error message when switching fails in mmc_select_hs()

The switch failure message in mmc_select_timing() had been removed
since that is invalid: commit 0400ed0a ("mmc: core: remove the
invalid message in mmc_select_timing")

Now, in the case when mmc_select_hs() return error in mmc_select_timing(),
there is nothing to print failure message.
Let's make for mmc_select_hs() print message itself in the failure case.

Signed-off-by: Jungseung Lee <js07.lee@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>