lavfi/vf_scale_qsv: remove PI, PHI and E

PI, PHI and E are defined in libavutil/eval.c, and user may use these
constants for scale_qsv filter, so we needn't re-define these variables
in vf_scale_qsv.c

Reviewed-by: Gyan Doshi <ffmpeg@gyani.pro>
Signed-off-by: Haihao Xiang <haihao.xiang@intel.com>

libavfilter/vf_scale_qsv.c

@@ -44,9 +44,6 @@
 #include "video.h"
 
 static const char *const var_names[] = {
-    "PI",
-    "PHI",
-    "E",
     "in_w",   "iw",
     "in_h",   "ih",
     "out_w",  "ow",
@@ -57,9 +54,6 @@ static const char *const var_names[] = {
 };
 
 enum var_name {
-    VAR_PI,
-    VAR_PHI,
-    VAR_E,
     VAR_IN_W,   VAR_IW,
     VAR_IN_H,   VAR_IH,
     VAR_OUT_W,  VAR_OW,
@@ -470,9 +464,6 @@ static int qsvscale_config_props(AVFilterLink *outlink)
     char *expr;
     int ret;
 
-    var_values[VAR_PI]    = M_PI;
-    var_values[VAR_PHI]   = M_PHI;
-    var_values[VAR_E]     = M_E;
     var_values[VAR_IN_W]  = var_values[VAR_IW] = inlink->w;
     var_values[VAR_IN_H]  = var_values[VAR_IH] = inlink->h;
     var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;