Make ff_mxf_pixel_layouts static to mxf.c.

Also make it an anonymous structure as never it is accessed by name.
Signed-off-by: Janne Grunau <janne-ffmpeg@jannau.net>
(cherry picked from commit a3dffc06)

libavformat/mxf.c

@@ -52,7 +52,10 @@ const MXFCodecUL ff_mxf_codec_uls[] = {
     { { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 },  0,       CODEC_ID_NONE },
 };
 
-const MXFPixelLayout ff_mxf_pixel_layouts[] = {
+static const struct {
+    enum PixelFormat pix_fmt;
+    const char data[16];
+} ff_mxf_pixel_layouts[] = {
     /**
      * See SMPTE 377M E.2.46
      *

libavformat/mxf.h

@@ -61,13 +61,6 @@ typedef struct {
 extern const MXFCodecUL ff_mxf_data_definition_uls[];
 extern const MXFCodecUL ff_mxf_codec_uls[];
 
-typedef struct {
-    enum PixelFormat pix_fmt;
-    const char data[16];
-} MXFPixelLayout;
-
-extern const MXFPixelLayout ff_mxf_pixel_layouts[];
-
 int ff_mxf_decode_pixel_layout(const char pixel_layout[16], enum PixelFormat *pix_fmt);
 
 #define PRINT_KEY(pc, s, x) dprintf(pc, "%s %02X %02X %02X %02X %02X %02X %02X %02X %02X %02X %02X %02X %02X %02X %02X %02X\n", s, \