cmd: mmc: fix typo 'a EMMC'

%s/a EMMC/an eMMC/g

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/cmd/mmc.c b/cmd/mmc.c
index 6f3cb85..1860a3f 100644
--- a/cmd/mmc.c
+++ b/cmd/mmc.c
@@ -264,7 +264,7 @@
 		return CMD_RET_FAILURE;
 
 	if (!(mmc->version & MMC_VERSION_MMC)) {
-		printf("It is not a EMMC device\n");
+		printf("It is not an eMMC device\n");
 		return CMD_RET_FAILURE;
 	}
 	if (mmc->version < MMC_VERSION_4_41) {
@@ -718,7 +718,7 @@
 		return CMD_RET_FAILURE;
 
 	if (IS_SD(mmc)) {
-		printf("It is not a EMMC device\n");
+		printf("It is not an eMMC device\n");
 		return CMD_RET_FAILURE;
 	}