efilinux: Stop printing "Error" when displaying usage

At the moment whenever efilinux exits after displaying either the
command argument syntax, the list of devices or prints the memory map
the following message is printed,

	"Error: Invalid Parameter"

Tidy up the exit path of parse_args() so that we can print these
useful bits of information without the user thinking that some kind of
error occurred.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>
1 file changed