x86/vga: fix mapping of the VGA text buffer

x86/vga: fix mapping of the VGA text buffer

The call to ioremap_wc() in video_init() will always fail, because
video_init() is called ahead of vm_init_type(), and so the underlying
__vmap() call will fail to allocate the linear address space.

Fix by reverting to the previous behavior and use __va() for the VGA text
buffer, as it's below the 1MB boundary, and thus always mapped in the
directmap.

Fixes: 81d195c6c0e2 ('x86: introduce ioremap_wc()')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 1ca5f69e35548e5196eadb329e5a3976821dc982
master date: 2025-03-20 17:16:10 +0100