UBI: do not support kiB

Be strict and accept only KiB, MiB and GiB, not Kib, not kib, etc.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 5098e6d..b967191 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -1038,10 +1038,8 @@
 	case 'M':
 		result *= 1024;
 	case 'K':
-	case 'k':
 		result *= 1024;
-		if (endp[1] == 'i' && (endp[2] == '\0' ||
-			  endp[2] == 'B'  || endp[2] == 'b'))
+		if (endp[1] == 'i' && endp[2] == 'B')
 			endp += 2;
 	case '\0':
 		break;