resource: Fix resource_size.cocci warnings

arch/x86/kernel/crash.c:627:34-37: ERROR: Missing resource_size with res
arch/x86/kernel/crash.c:528:16-19: ERROR: Missing resource_size with res

 Use resource_size function on resource object
 instead of explicit computation.

Generated by: scripts/coccinelle/api/resource_size.cocci

Fixes: 1d2e733b ("resource: Provide resource struct in resource walk callback")
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: kbuild-all@01.org
Cc: tipbuild@zytor.com
Cc: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20171107191801.GA91887@lkp-snb01