10l: fix make install with only shared libs

Originally committed as revision 22280 to svn://svn.ffmpeg.org/ffmpeg/trunk

subdir.mak

@@ -9,7 +9,6 @@ ifdef CONFIG_STATIC
 all: $(SUBDIR)$(LIBNAME)
 
 install-libs: install-lib$(NAME)-static
-install-headers: install-lib$(NAME)-headers install-lib$(NAME)-pkgconfig
 
 $(SUBDIR)$(LIBNAME): $(OBJS)
 	$(RM) $@
@@ -17,6 +16,8 @@ $(SUBDIR)$(LIBNAME): $(OBJS)
 	$(RANLIB) $@
 endif
 
+install-headers: install-lib$(NAME)-headers install-lib$(NAME)-pkgconfig
+
 INCINSTDIR := $(INCDIR)/lib$(NAME)
 
 THIS_LIB := $(SUBDIR)$($(CONFIG_SHARED:yes=S)LIBNAME)