Revert "selftest/vm: verify mmap addr in mremap_test"

Revert "selftest/vm: verify mmap addr in mremap_test"

This reverts commit e8b9989597daac896b3400b7005f24bf15233d9a.

The upstream commit 9c85a9bae267 ("selftest/vm: verify mmap addr in
mremap_test") was backported as commit a17404fcbfd0 ("selftest/vm:
verify mmap addr in mremap_test"). Repeated backport introduced the
duplicate of function get_mmap_min_addr to the file breakign the vm
selftest build.

Fixes: e8b9989597da ("selftest/vm: verify mmap addr in mremap_test")
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>