build: Fix compilation when configuring with a prog suffix

Fixes ticket #1676
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Makefile

@@ -15,7 +15,7 @@ PROGS-$(CONFIG_FFPLAY)   += ffplay
 PROGS-$(CONFIG_FFPROBE)  += ffprobe
 PROGS-$(CONFIG_FFSERVER) += ffserver
 
-PROGS      := $(PROGS-yes:%=%$(EXESUF))
+PROGS      := $(PROGS-yes:%=%$(PROGSSUF)$(EXESUF))
 INSTPROGS   = $(PROGS-yes:%=%$(PROGSSUF)$(EXESUF))
 OBJS        = cmdutils.o
 OBJS-ffmpeg = ffmpeg_opt.o ffmpeg_filter.o
@@ -52,9 +52,9 @@ FF_DEP_LIBS  := $(DEP_LIBS)
 
 all: $(PROGS)
 
-$(PROGS): %$(EXESUF): %$(PROGSSUF)_g$(EXESUF)
-	$(CP) $< $@$(PROGSSUF)
-	$(STRIP) $@$(PROGSSUF)
+$(PROGS): %$(EXESUF): %_g$(EXESUF)
+	$(CP) $< $@
+	$(STRIP) $@
 
 $(TOOLS): %$(EXESUF): %.o
 	$(LD) $(LDFLAGS) -o $@ $< $(ELIBS)
@@ -92,10 +92,10 @@ $(foreach D,$(FFLIBS),$(eval $(call DOSUBDIR,lib$(D))))
 
 define DOPROG
 OBJS-$(1) += $(1).o
-$(1)_g$(EXESUF): $(OBJS-$(1))
+$(1)$(PROGSSUF)_g$(EXESUF): $(OBJS-$(1))
 $$(OBJS-$(1)): CFLAGS  += $(CFLAGS-$(1))
-$(1)_g$(EXESUF): LDFLAGS += $(LDFLAGS-$(1))
-$(1)_g$(EXESUF): FF_EXTRALIBS += $(LIBS-$(1))
+$(1)$(PROGSSUF)_g$(EXESUF): LDFLAGS += $(LDFLAGS-$(1))
+$(1)$(PROGSSUF)_g$(EXESUF): FF_EXTRALIBS += $(LIBS-$(1))
 -include $$(OBJS-$(1):.o=.d)
 endef