lavfi: duplicate ff_log2_tab

Fixes compilation failures on msvc/icl shared builds

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/Makefile

@@ -244,6 +244,7 @@ SKIPHEADERS-$(CONFIG_LIBVIDSTAB)             += vidstabutils.h
 SKIPHEADERS-$(CONFIG_OPENCL)                 += opencl_internal.h deshake_opencl_kernel.h unsharp_opencl_kernel.h
 
 OBJS-$(HAVE_THREADS)                         += pthread.o
+OBJS-$(CONFIG_SHARED)                        += log2_tab.o
 
 TOOLS     = graph2dot
 TESTPROGS = drawutils filtfmts formats

libavfilter/log2_tab.c

@@ -0,0 +1 @@
+#include "libavutil/log2_tab.c"