x86/paravirt: Remove unnecessary return from void function

The patch removes unnecessary return from void function.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: ldv-project@linuxtesting.org
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/1498234993-1320-1-git-send-email-vasilyev@ispras.ru


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