mmc: core: remove duplicate code in mmc_rescan

If the card is removed, the wakelock has to be held for
an extended period of time to enable the user-space to
respond. The code to extend the wakelock has been
duplicated. This patch removes this duplicate code.

Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>