ffmpeg6: fix build for glibc and gcc14

srcpkgs/ffmpeg6/patches/v4l2-fix-glibc.patch

@@ -0,0 +1,17 @@
+libv4l2.h uses #ifdef, not #if
+
+diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c
+index 42d4b97c8f701..0ae68723382f4 100644
+--- a/libavdevice/v4l2.c
++++ b/libavdevice/v4l2.c
+@@ -47,6 +47,10 @@
+ #include "v4l2-common.h"
+ #include <dirent.h>
+ 
++#if ! HAVE_POSIX_IOCTL
++#undef HAVE_POSIX_IOCTL
++#endif
++
+ #if CONFIG_LIBV4L2
+ #include <libv4l2.h>
+ #endif