[finsh] Fixed RT-Thread spelling

components/finsh/cmd.c

@@ -55,7 +55,7 @@ long version(void)
 
     return 0;
 }
-MSH_CMD_EXPORT(version, show RT - Thread version information);
+MSH_CMD_EXPORT(version, show RT-Thread version information);
 
 rt_inline void object_split(int len)
 {

components/finsh/msh.c

@@ -52,7 +52,7 @@ int msh_help(int argc, char **argv)
 
     return 0;
 }
-MSH_CMD_EXPORT_ALIAS(msh_help, help, RT - Thread shell help.);
+MSH_CMD_EXPORT_ALIAS(msh_help, help, RT-Thread shell help.);
 
 #ifdef MSH_USING_BUILT_IN_COMMANDS
 int cmd_ps(int argc, char **argv)