USB: drivers/usb/serial/sierra.c: make 3 functions static

This patch makes three needlessly global functions static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Kevin Lloyd <linux@sierrawireless.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 file changed