configure: simplify -rpath-link linker flag

Lists of ':'-separated directories can be passed to -rpath-link directly.

configure

@@ -2958,7 +2958,7 @@ enabled extra_warnings && check_cflags -Winline
 
 # add some linker flags
 check_ldflags -Wl,--warn-common
-check_ldflags -Wl,-rpath-link,libpostproc -Wl,-rpath-link,libswscale -Wl,-rpath-link,libavfilter -Wl,-rpath-link,libavdevice -Wl,-rpath-link,libavformat -Wl,-rpath-link,libavcodec -Wl,-rpath-link,libavutil
+check_ldflags -Wl,-rpath-link=libpostproc:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil
 test_ldflags -Wl,-Bsymbolic && append SHFLAGS -Wl,-Bsymbolic
 
 echo "X{};" > $TMPV