go32-nat.c: Don't override to_open.

go32-nat.c: Don't override to_open.

Although the string says "Done.", nothing is pushing the target as is.
Removing the method override let's us fall through to the the base
to_open implemention in inf-child.c, which will push the target in
reaction to "target native" in a follow up patch.

gdb/
2014-05-21  Pedro Alves  <palves@redhat.com>

	* go32-nat.c (go32_open): Delete.
	(go32_target): Don't override the to_open method.