libbb: disable a second md5 implementation which managed to creep in :)

function                                             old     new   delta
sha512_end                                           239     237      -2
sha256_end                                           162     160      -2
sha1_end                                             191     189      -2
md5_end                                              168     166      -2
__md5__magic                                           4       -      -4
md5_crypt                                            627     621      -6
static.S                                              16       -     -16
__md5_Init                                            42       -     -42
static.P                                              64       -     -64
__md5_Final                                          131       -    -131
__md5_Update                                         153       -    -153
static.C                                             268      12    -256
__md5_Transform                                      293       -    -293
------------------------------------------------------------------------------
(add/remove: 0/7 grow/shrink: 0/6 up/down: 0/-973)           Total: -973 bytes

diff --git a/include/libbb.h b/include/libbb.h
index 839a0de..85a915e 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1309,7 +1309,7 @@
 } sha1_ctx_t;
 void sha1_begin(sha1_ctx_t *ctx) FAST_FUNC;
 void sha1_hash(const void *data, size_t length, sha1_ctx_t *ctx) FAST_FUNC;
-void *sha1_end(void *resbuf, sha1_ctx_t *ctx) FAST_FUNC;
+void sha1_end(void *resbuf, sha1_ctx_t *ctx) FAST_FUNC;
 typedef struct sha256_ctx_t {
 	uint32_t H[8];
 	uint32_t total[2]; /* rename to "count"? */
@@ -1318,7 +1318,7 @@
 } sha256_ctx_t;
 void sha256_begin(sha256_ctx_t *ctx) FAST_FUNC;
 void sha256_hash(const void *buffer, size_t len, sha256_ctx_t *ctx) FAST_FUNC;
-void* sha256_end(void *resbuf, sha256_ctx_t *ctx) FAST_FUNC;
+void sha256_end(void *resbuf, sha256_ctx_t *ctx) FAST_FUNC;
 typedef struct sha512_ctx_t {
 	uint64_t H[8];
 	uint64_t total[2];
@@ -1327,7 +1327,8 @@
 } sha512_ctx_t;
 void sha512_begin(sha512_ctx_t *ctx) FAST_FUNC;
 void sha512_hash(const void *buffer, size_t len, sha512_ctx_t *ctx) FAST_FUNC;
-void* sha512_end(void *resbuf, sha512_ctx_t *ctx) FAST_FUNC;
+void sha512_end(void *resbuf, sha512_ctx_t *ctx) FAST_FUNC;
+#if 1
 typedef struct md5_ctx_t {
 	uint32_t A;
 	uint32_t B;
@@ -1337,9 +1338,18 @@
 	uint32_t buflen;
 	char buffer[128];
 } md5_ctx_t;
+#else
+/* libbb/md5prime.c uses a bit different one: */
+typedef struct md5_ctx_t {
+	uint32_t state[4];	/* state (ABCD) */
+	uint32_t count[2];	/* number of bits, modulo 2^64 (lsb first) */
+	unsigned char buffer[64];	/* input buffer */
+} md5_ctx_t;
+#endif
 void md5_begin(md5_ctx_t *ctx) FAST_FUNC;
 void md5_hash(const void *data, size_t length, md5_ctx_t *ctx) FAST_FUNC;
-void *md5_end(void *resbuf, md5_ctx_t *ctx) FAST_FUNC;
+void md5_end(void *resbuf, md5_ctx_t *ctx) FAST_FUNC;
+
 
 uint32_t *crc32_filltable(uint32_t *tbl256, int endian) FAST_FUNC;