Don't use the interruptable version of the timeline mutex lock in the
error path of eb_pin_timeline as the cleanup must always happen.
v2:
 (John Harrison)
  - Don't check for interrupt during mutex lock
v3:
 (Tvrtko)
  - A comment explaining why lock helper isn't used
Fixes: 544460c33821 ("drm/i915: Multi-BB execbuf")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220111163929.14017-1-matthew.brost@intel.com
                                      timeout) < 0) {
                        i915_request_put(rq);
 
-                       tl = intel_context_timeline_lock(ce);
+                       /*
+                        * Error path, cannot use intel_context_timeline_lock as
+                        * that is user interruptable and this clean up step
+                        * must be done.
+                        */
+                       mutex_lock(&ce->timeline->mutex);
                        intel_context_exit(ce);
-                       intel_context_timeline_unlock(tl);
+                       mutex_unlock(&ce->timeline->mutex);
 
                        if (nonblock)
                                return -EWOULDBLOCK;