adfs: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

fs/adfs/dir_f.c

@@ -24,8 +24,11 @@ static inline unsigned int adfs_readval(unsigned char *p, int len)
 
 	switch (len) {
 	case 4:		val |= p[3] << 24;
+			/* fall through */
 	case 3:		val |= p[2] << 16;
+			/* fall through */
 	case 2:		val |= p[1] << 8;
+			/* fall through */
 	default:	val |= p[0];
 	}
 	return val;
@@ -35,8 +38,11 @@ static inline void adfs_writeval(unsigned char *p, int len, unsigned int val)
 {
 	switch (len) {
 	case 4:		p[3] = val >> 24;
+			/* fall through */
 	case 3:		p[2] = val >> 16;
+			/* fall through */
 	case 2:		p[1] = val >> 8;
+			/* fall through */
 	default:	p[0] = val;
 	}
 }