wininet: Change read_buf type to BYTE.

dlls/wininet/http.c

@@ -1697,7 +1697,7 @@ static BOOL read_line( WININETHTTPREQW *req, LPSTR buffer, DWORD *len )
     EnterCriticalSection( &req->read_section );
     for (;;)
     {
-        char *eol = memchr( req->read_buf + req->read_pos, '\n', req->read_size );
+        BYTE *eol = memchr( req->read_buf + req->read_pos, '\n', req->read_size );
 
         if (eol)
         {
@@ -1737,7 +1737,7 @@ static BOOL discard_eol( WININETHTTPREQW *req )
 {
     do
     {
-        char *eol = memchr( req->read_buf + req->read_pos, '\n', req->read_size );
+        BYTE *eol = memchr( req->read_buf + req->read_pos, '\n', req->read_size );
         if (eol)
         {
             remove_data( req, (eol + 1) - (req->read_buf + req->read_pos) );

dlls/wininet/internet.h

@@ -208,7 +208,7 @@ typedef struct
     BOOL  read_chunked;   /* are we reading in chunked mode? */
     DWORD read_pos;       /* current read position in read_buf */
     DWORD read_size;      /* valid data size in read_buf */
-    char  read_buf[4096]; /* buffer for already read but not returned data */
+    BYTE  read_buf[4096]; /* buffer for already read but not returned data */
 } WININETHTTPREQW, *LPWININETHTTPREQW;