Avoid the use of the symbol ff_expr_s for referencing AVExpr.

This way we have to deal only with struct AVExpr and AVExpr, which is
slightly less confusing as the association between the two symbols is
obvious.

Originally committed as revision 22839 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/eval.c

@@ -115,7 +115,7 @@ static int strmatch(const char *s, const char *prefix){
     return 1;
 }
 
-struct ff_expr_s {
+struct AVExpr {
     enum {
         e_value, e_const, e_func0, e_func1, e_func2,
         e_squish, e_gauss, e_ld,
@@ -130,7 +130,7 @@ struct ff_expr_s {
         double (*func1)(void *, double);
         double (*func2)(void *, double, double);
     } a;
-    AVExpr *param[2];
+    struct AVExpr *param[2];
 };
 
 static double eval_expr(Parser * p, AVExpr * e) {

libavcodec/eval.h

@@ -28,7 +28,7 @@
 #ifndef AVCODEC_EVAL_H
 #define AVCODEC_EVAL_H
 
-typedef struct ff_expr_s AVExpr;
+typedef struct AVExpr AVExpr;
 
 /**
  * Parses and evaluates an expression.