Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistent

Currently sysrq_enabled and __sysrq_enabled are initialised separately
and inconsistently, leading to sysrq being actually enabled by reported
as not enabled in sysfs.  The first change to the sysfs configurable
synchronises these two:

    static int __read_mostly sysrq_enabled = 1;
    static int __sysrq_enabled;

Add a common define to carry the default for these preventing them becoming
out of sync again.  Default this to 1 to mirror previous behaviour.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: stable@kernel.org
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/include/linux/sysrq.h b/include/linux/sysrq.h
index 387fa7d..7faf933 100644
--- a/include/linux/sysrq.h
+++ b/include/linux/sysrq.h
@@ -17,6 +17,9 @@
 #include <linux/errno.h>
 #include <linux/types.h>
 
+/* Enable/disable SYSRQ support by default (0==no, 1==yes). */
+#define SYSRQ_DEFAULT_ENABLE	1
+
 /* Possible values of bitmask for enabling sysrq functions */
 /* 0x0001 is reserved for enable everything */
 #define SYSRQ_ENABLE_LOG	0x0002