[ios] Fixed kHtmlWithMultiplePasswordForms test case.

According to test comments the action should only differ by query and
fragment, not by path.

BUG=None

Review-Url: https://codereview.chromium.org/2292483003
Cr-Commit-Position: refs/heads/master@{#415314}

ios/chrome/browser/passwords/password_controller_unittest.mm

@@ -707,7 +707,7 @@ static NSString* kHtmlWithMultiplePasswordForms =
      "<input id='un0' type='text' name='u0'>"
      "<input id='pw0' type='password' name='p0'>"
      "</form>"
-     "<form action='action?query=yes#reference'>"
+     "<form action='?query=yes#reference'>"
      "<input id='un1' type='text' name='u1'>"
      "<input id='pw1' type='password' name='p1'>"
      "</form>"