xen: No need to flush the mapcache for grants

xen: No need to flush the mapcache for grants

On IOREQ_TYPE_INVALIDATE we need to invalidate the mapcache for regular
mappings. Since recently we started reusing the mapcache also to keep
track of grants mappings. However, there is no need to remove grant
mappings on IOREQ_TYPE_INVALIDATE requests, we shouldn't do that. So
remove the function call.

Fixes: 9ecdd4bf08 (xen: mapcache: Add support for grant mappings)
Cc: qemu-stable@nongnu.org
Reported-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Message-Id: <20250206194915.3357743-2-edgar.iglesias@gmail.com>
Signed-off-by: Anthony PERARD <anthony.perard@vates.tech>
(cherry picked from commit 68adcc784bad13421ac7211c316a751fb99fcb94)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>