Enable PIC unconditionally on OpenBSD

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@19526 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

configure

@@ -1813,7 +1813,7 @@ case $target_os in
         ;;
     openbsd)
         enable malloc_aligned
-        LIBOBJFLAGS='$(PIC)'
+        enable pic
         SHFLAGS='-shared'
         oss_indev_extralibs="-lossaudio"
         oss_outdev_extralibs="-lossaudio"