x86: Don't check for BIOS corruption in first 64K when there's no need to

commit a7bd1dafdcc13ec7add4aafc927eb5e3a8d597e6 upstream.

Due to commit 781c5a67f152c17c3e4a9ed9647f8c0be6ea5ae9 it is
likely that the number of areas to scan for BIOS corruption is 0
 -- especially when the first 64K is already reserved
(X86_RESERVE_LOW is 64K by default).

If that's the case then don't set up the scan.

Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
LKML-Reference: <20110225202838.2229.71011.sendpatchset@nchumbalkar.americas.hpqcorp.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>