tools/lib/lockdep: Fix 'defined but not used' warning for init_utsname()

We define init_utsname() as static but not inline, resulting
in a warning for every source file that includes lockdep.h but
doesn't call it.

Since it is only used by lockdep.c, define it in there.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: a.p.zijlstra@chello.nl
Link: http://lkml.kernel.org/r/20170525130005.5947-8-alexander.levin@verizon.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>