drm/tegra: hub: Use fn parameter directly to fix Coccinelle warning

The function parameter out can be used directly instead of assigning it
to a temporary u64 variable first.

Remove the local variable tmp2 and use the parameter out directly as the
divisor in do_div() to remove the following Coccinelle/coccicheck
warning reported by do_div.cocci:

  WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240710210034.796032-2-thorsten.blum@toblux.com

drivers/gpu/drm/tegra/hub.c

@@ -521,12 +521,11 @@ static void tegra_shared_plane_atomic_disable(struct drm_plane *plane,
 
 static inline u32 compute_phase_incr(fixed20_12 in, unsigned int out)
 {
-	u64 tmp, tmp1, tmp2;
+	u64 tmp, tmp1;
 
 	tmp = (u64)dfixed_trunc(in);
-	tmp2 = (u64)out;
-	tmp1 = (tmp << NFB) + (tmp2 >> 1);
-	do_div(tmp1, tmp2);
+	tmp1 = (tmp << NFB) + ((u64)out >> 1);
+	do_div(tmp1, out);
 
 	return lower_32_bits(tmp1);
 }