libswresample.v: add swresample* for cmdutils.c

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

libswresample/libswresample.v

@@ -1,4 +1,4 @@
 LIBSWRESAMPLE_$MAJOR {
-        global: swr_*; ff_*;
+        global: swr_*; ff_*; swresample_*;
         local: *;
 };