src/md5.c: Address warning -Wold-style-definition

Symptom was:
> md5.c: In function 'MD5Init':
> md5.c:83:6: warning: old-style function definition [-Wold-style-definition]
>    83 | void MD5Init (mdContext)
>       |      ^~~~~~~
> md5.c: In function 'MD5Update':
> md5.c:96:6: warning: old-style function definition [-Wold-style-definition]
>    96 | void MD5Update (mdContext, inBuf, inLen)
>       |      ^~~~~~~~~
> [..]
> md5.c: In function 'MD5Final':
> md5.c:131:6: warning: old-style function definition [-Wold-style-definition]
>   131 | void MD5Final (mdContext, buf)
>       |      ^~~~~~~~
> [..]
> md5.c: In function 'MD5Sprint':
> md5.c:175:6: warning: old-style function definition [-Wold-style-definition]
>   175 | void MD5Sprint (mdContext, buf)
>       |      ^~~~~~~~~
> md5.c: In function 'Transform':
> md5.c:187:13: warning: old-style function definition [-Wold-style-definition]
>   187 | static void Transform (buf, in)
>       |             ^~~~~~~~~

Author: hartwork

src/md5.c

@@ -80,8 +80,7 @@ static unsigned char PADDING[64] = {
    (a) += (b); \
   }
 
-void MD5Init (mdContext)
-MD5_CTX *mdContext;
+void MD5Init (MD5_CTX *mdContext)
 {
   mdContext->i[0] = mdContext->i[1] = (UINT4)0;
 
@@ -93,10 +92,7 @@ MD5_CTX *mdContext;
   mdContext->buf[3] = (UINT4)0x10325476;
 }
 
-void MD5Update (mdContext, inBuf, inLen)
-MD5_CTX *mdContext;
-const unsigned char *inBuf;
-unsigned int inLen;
+void MD5Update (MD5_CTX *mdContext, const unsigned char *inBuf, unsigned int inLen)
 {
   UINT4 in[16];
   int mdi;
@@ -128,9 +124,7 @@ unsigned int inLen;
   }
 }
 
-void MD5Final (mdContext, buf)
-MD5_CTX *mdContext;
-char *buf;
+void MD5Final (MD5_CTX *mdContext, char *buf)
 {
   UINT4 in[16];
   int mdi;
@@ -172,9 +166,7 @@ char *buf;
 
 /* Print the context to the given buffer (32 digits)
  */
-void MD5Sprint (mdContext, buf)
-MD5_CTX *mdContext;
-char *buf;
+void MD5Sprint (MD5_CTX *mdContext, char *buf)
 {
      int i;
 
@@ -184,9 +176,7 @@ char *buf;
 
 /* Basic MD5 step. Transform buf based on in.
  */
-static void Transform (buf, in)
-UINT4 *buf;
-UINT4 *in;
+static void Transform (UINT4 *buf, UINT4 *in)
 {
   UINT4 a = buf[0], b = buf[1], c = buf[2], d = buf[3];