Be minimalistic wrt LDFLAGS

Passing CFLAGS and LDFLAGS to kpdfview link stage has no effect in our
particular case, so I ripped it out, leaving it only for the crengine.

Makefile

@@ -92,7 +92,6 @@ all:kpdfview
 
 kpdfview: kpdfview.o einkfb.o pdf.o blitbuffer.o drawcontext.o input.o util.o ft.o lfs.o mupdfimg.o $(MUPDFLIBS) $(THIRDPARTYLIBS) $(LUALIB) djvu.o $(DJVULIBS) cre.o $(CRENGINELIBS)
 	$(CC) \
-		$(CFLAGS) \
 		kpdfview.o \
 		einkfb.o \
 		pdf.o \
@@ -111,7 +110,6 @@ kpdfview: kpdfview.o einkfb.o pdf.o blitbuffer.o drawcontext.o input.o util.o ft
 		cre.o \
 		$(CRENGINELIBS) \
 		$(STATICLIBSTDCPP) \
-		$(LDFLAGS) \
 		-o kpdfview -lm -ldl -lpthread $(EMU_LDFLAGS) $(DYNAMICLIBSTDCPP)
 
 slider_watcher: slider_watcher.c