Fix leftover remote test failures from PR binutils/19020

Fix leftover remote test failures from PR binutils/19020

As pointed out in PR binutils/19020, those tests were still failing when doing
remote testing. This is because the binary files weren't being copied over to
the remote host for testing.

FAIL: binutils-all/pr19020a
FAIL: binutils-all/pr19020b

This small patch fixes this up to make things pass.

binutils/ChangeLog:
2016-10-14  Luis Machado  <lgustavo@codesourcery.com>

	* testsuite/lib/utils-lib.exp (run_dump_test): Call remote_download
	to copy file to remote host.