http: Declare more parameters as const where possible

Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/http.c

@@ -353,7 +353,7 @@ static int parse_location(HTTPContext *s, const char *p)
 }
 
 /* "bytes $from-$to/$document_size" */
-static void parse_content_range(URLContext *h, char *p)
+static void parse_content_range(URLContext *h, const char *p)
 {
     HTTPContext *s = h->priv_data;
     const char *slash;
@@ -367,7 +367,7 @@ static void parse_content_range(URLContext *h, char *p)
     h->is_streamed = 0; /* we _can_ in fact seek */
 }
 
-static int parse_content_encoding(URLContext *h, char *p)
+static int parse_content_encoding(URLContext *h, const char *p)
 {
     HTTPContext *s = h->priv_data;