linux-user: fix tcg/mmap test

tests/tcg/mmap test fails with values other than default target page
size. When creating a map beyond EOF, extra anonymous pages are added up
to the target page boundary. Currently, this operation is performed only
when qemu_real_host_page_size < TARGET_PAGE_SIZE, but it should be
performed if the configured page size (qemu -p) is larger than
qemu_real_host_page_size too.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[pranith: dropped checkpatch changes]
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20170119151533.29328-2-bobby.prani@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
