Merge gate page refcount fix from Dave Hansen:
 "During the conversion over to pin_user_pages(), gate pages were missed.

  The fix is pretty simple, and is accompanied by a new test from Andy
  which probably would have caught this earlier"

* emailed patches from Dave Hansen <dave.hansen@linux.intel.com>:
  selftests/x86/test_vsyscall: Improve the process_vm_readv() test
  mm: fix pin vs. gup mismatch with gate pages