i386/kexec-mb2-x86.c: Fix compilation warning

This patch fixes the following compilation warning in
'i386/kexec-mb2-x86.c' regarding the variable 'result'
which is set but not used:

kexec/arch/i386/kexec-mb2-x86.c:402:6:
 warning: variable ‘result’ set but not used [-Wunused-but-set-variable]
  int result;
      ^~~~~~

Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Simon Horman <horms@verge.net.au>