USB: resume_device symbol conflict

Several functions in USB core overlap with global functions.
The linker appears to do the right thing, but it is bad practice and makes
debugging harder.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>