mmc: sdhci-pci: remove redundant check of slots == 0

mmc: sdhci-pci: remove redundant check of slots == 0

The calculation of slots results in a value in the range 1..8
and so slots can never be zero.  The check for slots == 0 is
always going to be false, hence it is redundant and can be
removed.

Addresses-Coverity: ("Logically dead code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>