x86/mce: Add a wrapper around mce_log() for injection

Will be used by an injector module in a following patch.

Additionally, add a missing module export reported by 0-DAY
kernel test.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1439396985-12812-13-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/mcheck/mce-internal.h

@@ -79,3 +79,5 @@ static inline int apei_clear_mce(u64 record_id)
 	return -EINVAL;
 }
 #endif
+
+void mce_inject_log(struct mce *m);

arch/x86/kernel/cpu/mcheck/mce.c

@@ -199,6 +199,14 @@ void mce_log(struct mce *mce)
 	set_bit(0, &mce_need_notify);
 }
 
+void mce_inject_log(struct mce *m)
+{
+	mutex_lock(&mce_chrdev_read_mutex);
+	mce_log(m);
+	mutex_unlock(&mce_chrdev_read_mutex);
+}
+EXPORT_SYMBOL_GPL(mce_inject_log);
+
 static struct notifier_block mce_srao_nb;
 
 void mce_register_decode_chain(struct notifier_block *nb)