mmc: make one-bit signed bitfields unsigned

Otherwise it can only take the values 0/-1 which doesn't seem to
have been intended.

drivers/mmc/host/sdhci.h:190:20: error: dubious one-bit signed bitfield
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Pierre Ossman <drzeus-list@drzeus.cx>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/mmc/host/sdhci.h

@@ -187,7 +187,7 @@ struct sdhci_host {
 	struct mmc_request	*mrq;		/* Current request */
 	struct mmc_command	*cmd;		/* Current command */
 	struct mmc_data		*data;		/* Current data request */
-	int			data_early:1;	/* Data finished before cmd */
+	unsigned int		data_early:1;	/* Data finished before cmd */
 
 	struct scatterlist	*cur_sg;	/* We're working on this */
 	int			num_sg;		/* Entries left */