x86: fix usage of bios intcall()

Some intcall() misuses the input biosregs as output in
cf06de7b9cdd3efee7a59dced1977b3c21d43732

This fixes the problem vga=ask boot option doesn't show enough modes.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
LKML-Reference: <20090701021307.GA3127@localhost.localdomain>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/boot/video-bios.c b/arch/x86/boot/video-bios.c
index d660be4..49e0c18 100644
--- a/arch/x86/boot/video-bios.c
+++ b/arch/x86/boot/video-bios.c
@@ -37,14 +37,13 @@
 	ireg.al = mode;		/* AH=0x00 Set Video Mode */
 	intcall(0x10, &ireg, NULL);
 
-
 	ireg.ah = 0x0f;		/* Get Current Video Mode */
 	intcall(0x10, &ireg, &oreg);
 
 	do_restore = 1;		/* Assume video contents were lost */
 
 	/* Not all BIOSes are clean with the top bit */
-	new_mode = ireg.al & 0x7f;
+	new_mode = oreg.al & 0x7f;
 
 	if (new_mode == mode)
 		return 0;	/* Mode change OK */