[finsh] Fix compiling issue in finsh.

components/finsh/SConscript

@@ -28,10 +28,10 @@ msh.c
 
 CPPPATH = [cwd]
 if rtconfig.CROSS_TOOL == 'keil':
-    LINKFLAGS = ' --keep __fsym_*'
+    LINKFLAGS = ' --keep *.o(FSymTab)'
 
     if not GetDepend('FINSH_USING_MSH_ONLY'):
-        LINKFLAGS = LINKFLAGS + ' --keep __vsym_* '
+        LINKFLAGS = LINKFLAGS + ' --keep *.o(VSymTab) '
 else:
     LINKFLAGS = '' 
 

components/finsh/msh_cmd.c

@@ -280,6 +280,7 @@ FINSH_FUNCTION_EXPORT_ALIAS(cmd_time, __cmd_time, Execute command with time.);
 int cmd_free(int argc, char** argv)
 {
     extern void list_mem(void);
+    extern void list_memheap(void);
 
 #ifdef RT_USING_MEMHEAP_AS_HEAP
     list_memheap();