Fix incorrect offset for vec3 datatypes in `_fill_std140_ubo_empty`

drivers/gles3/storage/material_storage.cpp

@@ -897,7 +897,9 @@ _FORCE_INLINE_ static void _fill_std140_ubo_empty(ShaderLanguage::DataType type,
 		case ShaderLanguage::TYPE_BVEC3:
 		case ShaderLanguage::TYPE_IVEC3:
 		case ShaderLanguage::TYPE_UVEC3:
-		case ShaderLanguage::TYPE_VEC3:
+		case ShaderLanguage::TYPE_VEC3: {
+			memset(data, 0, 12 * p_array_size);
+		} break;
 		case ShaderLanguage::TYPE_BVEC4:
 		case ShaderLanguage::TYPE_IVEC4:
 		case ShaderLanguage::TYPE_UVEC4:

servers/rendering/renderer_rd/storage_rd/material_storage.cpp

@@ -903,7 +903,9 @@ _FORCE_INLINE_ static void _fill_std140_ubo_empty(ShaderLanguage::DataType type,
 		case ShaderLanguage::TYPE_BVEC3:
 		case ShaderLanguage::TYPE_IVEC3:
 		case ShaderLanguage::TYPE_UVEC3:
-		case ShaderLanguage::TYPE_VEC3:
+		case ShaderLanguage::TYPE_VEC3: {
+			memset(data, 0, 12 * p_array_size);
+		} break;
 		case ShaderLanguage::TYPE_BVEC4:
 		case ShaderLanguage::TYPE_IVEC4:
 		case ShaderLanguage::TYPE_UVEC4: