GCC47: Fix warning in md5.c

md5.c: In function ‘MD5Final’:
md5.c:156:2: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
md5.c:157:2: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>

include/u-boot/md5.h

@@ -11,7 +11,10 @@
 struct MD5Context {
 	__u32 buf[4];
 	__u32 bits[2];
-	unsigned char in[64];
+	union {
+		unsigned char in[64];
+		__u32 in32[16];
+	};
 };
 
 /*

lib/md5.c

@@ -153,8 +153,8 @@ MD5Final(unsigned char digest[16], struct MD5Context *ctx)
 	byteReverse(ctx->in, 14);
 
 	/* Append length in bits and transform */
-	((__u32 *) ctx->in)[14] = ctx->bits[0];
-	((__u32 *) ctx->in)[15] = ctx->bits[1];
+	ctx->in32[14] = ctx->bits[0];
+	ctx->in32[15] = ctx->bits[1];
 
 	MD5Transform(ctx->buf, (__u32 *) ctx->in);
 	byteReverse((unsigned char *) ctx->buf, 4);