libavutil/channel_layout: Correctly return layout when channel specification ends with a trailing 'c'.

Return layout when FF_API_GET_CHANNEL_LAYOUT_COMPAT is set even if the
layout itself is not in the deprecated style.

Signed-off-by: Simon Thelen <ffmpeg-dev@c-14.de>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 83307a32eb)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavutil/channel_layout.c

@@ -138,8 +138,8 @@ static uint64_t get_channel_layout_single(const char *name, int name_len)
                        "switch to the syntax '%.*sc' otherwise it will be interpreted as a "
                        "channel layout number in a later version\n",
                        name_len, name, name_len, name);
-                return layout;
             }
+            return layout;
         }
     } else {
 #endif