advapi32: Constify a parameter

[Andrew Talbot]

This patch declares the buffer parameter of A_SHAUpdate() to be of the
same type as those in the equivalent MD4 and MD5 functions. If this patch
is accepted, I intend to modify A_SHAUpdate() in rsaenh/implglue.c in the
same way, to fix a cast-qual warning there.

-- Andy.
---
Changelog:
    advapi32: Constify a parameter.

diff -urN a/dlls/advapi32/crypt_sha.c b/dlls/advapi32/crypt_sha.c
--- a/dlls/advapi32/crypt_sha.c	2006-10-12 11:48:22.000000000 +0100
+++ b/dlls/advapi32/crypt_sha.c	2006-11-11 15:35:04.000000000 +0000
@@ -135,7 +135,7 @@
  *  Nothing
  */
 VOID WINAPI
-A_SHAUpdate(PSHA_CTX Context, PCHAR Buffer, UINT BufferSize)
+A_SHAUpdate(PSHA_CTX Context, const unsigned char *Buffer, UINT BufferSize)
 {
    ULONG BufferContentSize;
 
@@ -199,7 +199,7 @@
    Count = (ULONG*)(Buffer + Pad);
    Count[0] = DWORD2BE(LengthHi);
    Count[1] = DWORD2BE(LengthLo);
-   A_SHAUpdate(Context, (PCHAR)Buffer, Pad + 8);
+   A_SHAUpdate(Context, Buffer, Pad + 8);
 
    for (Index = 0; Index < 5; Index++)
       Result[Index] = DWORD2BE(Context->State[Index]);