uml: make three functions static

Make the following three functions static, since they don't need to be global.

arch/um/drivers/mcast_kern.c::mcast_setup()
arch/um/drivers/mconsole_user.c::mconsole_reply_v0()
arch/um/drivers/port_user.c::port_pre_exec()

Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/drivers/mcast_kern.c b/arch/um/drivers/mcast_kern.c
index 822092f..8c4378a 100644
--- a/arch/um/drivers/mcast_kern.c
+++ b/arch/um/drivers/mcast_kern.c
@@ -58,7 +58,7 @@
 	.write			= mcast_write,
 };
 
-int mcast_setup(char *str, char **mac_out, void *data)
+static int mcast_setup(char *str, char **mac_out, void *data)
 {
 	struct mcast_init *init = data;
 	char *port_str = NULL, *ttl_str = NULL, *remain;