www/firefox: fix build on powerpc64*

SupportsMimeType() now uses one argument.

www/firefox/files/patch-dom_media_flac_FlacDecoder.cpp

@@ -1,8 +1,6 @@
 Enable FLAC on platforms without ffvpx like powerpc*
 
-diff --git dom/media/flac/FlacDecoder.cpp dom/media/flac/FlacDecoder.cpp
-index 53fc3c9937f7..b23771ab80fa 100644
---- dom/media/flac/FlacDecoder.cpp
+--- dom/media/flac/FlacDecoder.cpp.orig	2021-04-15 19:44:28 UTC
 +++ dom/media/flac/FlacDecoder.cpp
 @@ -7,6 +7,7 @@
  #include "FlacDecoder.h"
@@ -12,15 +10,14 @@ index 53fc3c9937f7..b23771ab80fa 100644
  
  namespace mozilla {
  
-@@ -14,6 +15,11 @@ namespace mozilla {
+@@ -14,6 +15,10 @@ namespace mozilla {
  bool FlacDecoder::IsEnabled() {
  #ifdef MOZ_FFVPX
    return StaticPrefs::media_flac_enabled();
 +#elif defined(MOZ_FFMPEG)
 +  RefPtr<PDMFactory> platform = new PDMFactory();
 +  return StaticPrefs::media_flac_enabled() &&
-+         platform->SupportsMimeType("audio/flac"_ns,
-+                                    /* DecoderDoctorDiagnostics* */ nullptr);
++         platform->SupportsMimeType("audio/flac"_ns);
  #else
-   // Until bug 1295886 is fixed.
    return false;
+ #endif