libmd: build with WARNS=1

- build with WARNS=1. This works without any changes
- remove two unused variables noticed at WARNS=2

lib/libmd/Makefile

@@ -15,7 +15,7 @@ SRCS=	md4c.c md5c.c md4hl.c md5hl.c \
 INCS=	md4.h md5.h ripemd.h sha.h sha256.h sha384.h sha512.h sha512t.h \
 	skein.h skein_port.h skein_freebsd.h skein_iv.h
 
-WARNS?=	0
+WARNS?=	1
 
 MAN+=	md4.3 md5.3 ripemd.3 sha.3 sha256.3 sha512.3 skein.3
 MLINKS+=md4.3 MD4Init.3 md4.3 MD4Update.3 md4.3 MD4Final.3

lib/libmd/mdXhl.c

@@ -54,8 +54,7 @@ MDXFdChunk(int fd, char *buf, off_t ofs, off_t len)
 {
 	unsigned char buffer[16*1024];
 	MDX_CTX ctx;
-	struct stat stbuf;
-	int readrv, e;
+	int readrv;
 	off_t remain;
 
 	if (len < 0) {