build: Avoid detecting bogus components named 'x'

The function find_things() in configure is confused by component
registration calls as part of multiline macros defining combined
component registration.  Coalesce those macros into one line to
work around the issue.
Signed-off-by: Diego Biurrun <diego@biurrun.de>
Signed-off-by: Martin Storsjö <martin@martin.st>

libavcodec/allcodecs.c

@@ -48,9 +48,7 @@
             avcodec_register(&ff_##x##_decoder);                        \
     }
 
-#define REGISTER_ENCDEC(X, x)                                           \
-    REGISTER_ENCODER(X, x);                                             \
-    REGISTER_DECODER(X,x)
+#define REGISTER_ENCDEC(X, x) REGISTER_ENCODER(X, x); REGISTER_DECODER(X, x)
 
 #define REGISTER_PARSER(X, x)                                           \
     {                                                                   \

libavdevice/alldevices.c

@@ -36,9 +36,7 @@
             av_register_input_format(&ff_##x##_demuxer);                \
     }
 
-#define REGISTER_INOUTDEV(X, x)                                         \
-    REGISTER_OUTDEV(X, x);                                              \
-    REGISTER_INDEV(X, x)
+#define REGISTER_INOUTDEV(X, x) REGISTER_OUTDEV(X, x); REGISTER_INDEV(X, x)
 
 void avdevice_register_all(void)
 {

libavformat/allformats.c

@@ -39,9 +39,7 @@
             av_register_input_format(&ff_##x##_demuxer);                \
     }
 
-#define REGISTER_MUXDEMUX(X, x)                                         \
-    REGISTER_MUXER(X, x);                                               \
-    REGISTER_DEMUXER(X,x)
+#define REGISTER_MUXDEMUX(X, x) REGISTER_MUXER(X, x); REGISTER_DEMUXER(X, x)
 
 #define REGISTER_PROTOCOL(X, x)                                         \
     {                                                                   \