Make shared lib name handling consistent with the other Makefiles.

patch by Jacob Meuser <  jakemsr  ..@..  jakemsr  ...  com  >

Originally committed as revision 4831 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/libpostproc/Makefile

@@ -12,7 +12,7 @@ SHFLAGS += -Wl,-install_name,$(libdir)/$(SPPLIBNAME),-current_version,$(SPPVERSI
 else
 SPPLIBMAJOR = $(SPPLIBNAME).$(SPPMAJOR)
 SPPLIB = $(SPPLIBNAME).$(SPPVERSION)
-SHFLAGS = -shared -Wl,-soname,$(SPPLIB)
+LIBVERSION = $(SPPLIB)
 endif
 endif
 PPLIB = $(LIBPREF)postproc$(LIBSUF)