fixed kservice.c compiling error for gcc

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@482 bbd45198-f89e-11dd-88c7-29a3b14d5316

src/kservice.c

@@ -939,7 +939,7 @@ rt_device_t rt_console_set_device(const char* name)
 }
 
 #if defined(__GNUC__)
-void rt_hw_console_output(const char* str) __attribute__((weak))
+void __attribute__((weak)) rt_hw_console_output(const char* str)
 #elif defined(__CC_ARM)
 __weak void rt_hw_console_output(const char* str)
 #elif defined(__ICCARM__)