[Lut] SkImageInfo width was wrong.

- should be `length`, we over allocated before

Bug: 391438603
Bug: 393985848
Test: play with HDR10 blink test on GPU; play HDR video and rotate
Flag: EXEMPT small fix

Change-Id: I98aa8382ad24dab2ab82ab6868f6ac77a11db708

Author: Sally Qi

libs/renderengine/skia/filters/LutShader.cpp

@@ -182,8 +182,8 @@ sk_sp<SkShader> LutShader::generateLutShader(sk_sp<SkShader> input,
      * (R1, G1, B1, 0)
      * ...
      */
-    SkImageInfo info = SkImageInfo::Make(length /* the number of rgba */ * 4, 1,
-                                         kRGBA_F16_SkColorType, kPremul_SkAlphaType);
+    SkImageInfo info = SkImageInfo::Make(length /* the number of rgba */, 1, kRGBA_F16_SkColorType,
+                                         kPremul_SkAlphaType);
     SkBitmap bitmap;
     bitmap.allocPixels(info);
     if (!bitmap.installPixels(info, buffer.data(), info.minRowBytes())) {