From: Jorn Engel <joern@wohnheim.fh-wedel.de>

 AS	arch/i386/boot/setup.o
/usr/src/linux-2.6.5/arch/i386/boot/setup.S: Assembler messages:
/usr/src/linux-2.6.5/arch/i386/boot/setup.S:159: Warning: value 0x37ffffff truncated to 0x37ffffff

The warning is correct, the calculated value for ramdisk_max would be
0xb7ffffff instead of 0x37ffffff.  Truncating 0xb7ffffff to 0x37ffffff
is desired behaviour, so we should do it explicitly.