mmc: Fix comment typo

%s/occured/occurred/

Signed-off-by: Naoki Hayama <naoki.hayama@lineo.co.jp>
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index c46fa4e..a47700e 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -2192,7 +2192,7 @@
 				return 0;
 error:
 			mmc_set_signal_voltage(mmc, old_voltage);
-			/* if an error occured, revert to a safer bus mode */
+			/* if an error occurred, revert to a safer bus mode */
 			mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL,
 				   EXT_CSD_BUS_WIDTH, EXT_CSD_BUS_WIDTH_1);
 			mmc_select_mode(mmc, MMC_LEGACY);