sched/cpufreq/schedutil: Fix error path mutex unlock

sched/cpufreq/schedutil: Fix error path mutex unlock

This patch prevents the 'global_tunables_lock' mutex from being
unlocked before being locked.  This mutex is not locked if the
sugov_kthread_create() function fails.

Signed-off-by: Jules Maselbas <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: Chris Redpath <[email protected]>
Cc: Dietmar Eggermann <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Patrick Bellasi <[email protected]>
Cc: Stephen Kyle <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>