efi: sysfb_efi: Fix lfb_linelength calculation when applying quirks

PIXEL_BIT_MASK formats can have either less or more than four bytes per
pixel so lets fix the lfb_linelenght calculation when applying the
swapped width and height quirks.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Melissa Wen <mwen@igalia.com>
Cc: linux-efi@vger.kernel.org
Tested-by: Melissa Wen <mwen@igalia.com> # v3
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Author: Tvrtko Ursulin

drivers/firmware/efi/sysfb_efi.c

@@ -357,8 +357,11 @@ __init void sysfb_apply_efi_quirks(void)
 
 	if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
 	    dmi_check_system(efifb_dmi_swap_width_height)) {
+		u32 bpp = __screen_info_lfb_bits_per_pixel(&screen_info);
+
 		swap(screen_info.lfb_width, screen_info.lfb_height);
-		screen_info.lfb_linelength = 4 * screen_info.lfb_width;
+		screen_info.lfb_linelength = bpp * screen_info.lfb_width /
+					     BITS_PER_BYTE;
 	}
 }