avutil/hwcontext_qsv: Remove redundant check

It has already been checked immediately before that said
AVDictionaryEntry exists; checking again is redundant.
Furthermore, av_hwdevice_find_type_by_name() requires its argument
to be non-NULL, so adding a codepath that automatically calls it
with that parameter is nonsense. The same goes for the argument
corresponding to %s.

Fixes Coverity issue 1491394.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavutil/hwcontext_qsv.c

@@ -1463,10 +1463,10 @@ static int qsv_device_create(AVHWDeviceContext *ctx, const char *device,
 
     e = av_dict_get(opts, "child_device_type", NULL, 0);
     if (e) {
-        child_device_type = av_hwdevice_find_type_by_name(e ? e->value : NULL);
+        child_device_type = av_hwdevice_find_type_by_name(e->value);
         if (child_device_type == AV_HWDEVICE_TYPE_NONE) {
             av_log(ctx, AV_LOG_ERROR, "Unknown child device type "
-                   "\"%s\".\n", e ? e->value : NULL);
+                   "\"%s\".\n", e->value);
             return AVERROR(EINVAL);
         }
     } else if (CONFIG_VAAPI) {