EDAC, mce_amd_inj: Make inj_type static

It is used there only anyway.

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: kbuild-all@01.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20150605112426.GA97073@lkp-sb04


Signed-off-by: Borislav Petkov <bp@suse.de>