mmc: core: Don't release clock when retrying a failed request

The mmc clock would get released when request processing is done.
In case of error, the request starter may retry the request.
In case of failed requests, clock is getting requested only once
but its getting released multiple times due to retries. This is
leading to unbalance in clock requests due to which clock gating
is misbehaving.

Update the condition so that clock won't get released in case of
request retries.

Change-Id: I1e0eba1afcfc012b9d840b777f768c7188c63c78
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>