[PATCH] drm/i915: mark wait_for_engine() __maybe_unused

[Nick Desaulniers <nick.desaulniers@gmail.com>]

This solves a warning when compiling the driver with Clang, -Werror enabled,
and CONFIG_DRM_I915_DEBUG_GEM unset, since Clang warns that:

drivers/gpu/drm/i915/i915_gem.c:3274:12: error: function
'wait_for_engine' is not needed
      and will not be emitted [-Werror,-Wunneeded-internal-declaration]
static int wait_for_engine(struct intel_engine_cs *engine, int
timeout_ms)
           ^

Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com>
---
Additionally, it only has one call site. Should I mark it inline, too, while
I'm at it?

 drivers/gpu/drm/i915/i915_gem.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index b6ac3df18b58..73b82fb94b0e 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3271,7 +3271,8 @@ static int wait_for_timeline(struct i915_gem_timeline *tl, unsigned int flags)
 	return 0;
 }
 
-static int wait_for_engine(struct intel_engine_cs *engine, int timeout_ms)
+static __maybe_unused int wait_for_engine(
+	struct intel_engine_cs *engine, int timeout_ms)
 {
 	return wait_for(intel_engine_is_idle(engine), timeout_ms);
 }
-- 
2.11.0