anv: Rename a variable

The name "desc" shadows another variable.  Name it "desc_data" like all
of the other descriptor data variables in this file.
38 jobs for !3610 with jenkins_vulkan in 26 minutes and 26 seconds (queued for 5 seconds)
detached
Status Job ID Name Coverage
  Container
passed #1496785
aarch64
arm_build

00:00:19

passed #1496786
aarch64
arm_test

00:00:20

passed #1496782
x86_build

00:00:23

passed #1496784
x86_build_old

00:00:23

passed #1496783
x86_test-gl

00:00:24

 
  Build
passed #1496790
aarch64
meson-arm64

00:11:18

passed #1496789
aarch64
meson-armhf

00:11:30

passed #1496791
meson-clang

00:08:05

passed #1496794
meson-clover

00:06:04

passed #1496795
meson-clover-old-llvm

00:04:50

passed #1496797
meson-i386

00:03:27

passed #1496788
meson-main

00:07:37

passed #1496798
meson-mingw32-x86_64

00:04:11

passed #1496787
meson-testing

00:05:48

passed #1496796
meson-vulkan

00:05:01

passed #1496799
scons

00:04:55

passed #1496800
scons-old-llvm

00:03:03

passed #1496792
scons-swr

00:05:30

passed #1496793
scons-win64

00:05:33

 
  Test
passed #1496819
db410c
arm64_a306_gles2

00:06:13

passed #1496816
mesa-cheza
arm64_a630_gles2

00:01:45

passed #1496818
mesa-cheza
arm64_a630_gles3

00:14:41

passed #1496817
mesa-cheza
arm64_a630_gles31

00:04:39

passed #1496804
lava-meson-gxl-s905x-libretech-cc
lima-mali450-test:arm64

00:08:25

passed #1496801
lava-sun50i-h6-pine-h64
panfrost-t720-test:arm64

00:08:35

passed #1496802
lava-rk3288-veyron-jaq
panfrost-t760-test:armhf

00:06:27

passed #1496803
lava-rk3399-gru-kevin
panfrost-t860-test:arm64

00:05:35

passed #1496806
piglit-glslparser

00:04:45

passed #1496805
piglit-quick_gl

00:10:00

passed #1496807
piglit-quick_shader

00:06:21

passed #1496808
test-llvmpipe-gles2

00:05:41

passed #1496809
test-softpipe-gles2

00:01:37

passed #1496812
test-softpipe-gles31 1/4

00:04:18

passed #1496810
test-softpipe-gles3 1/2

00:05:10

passed #1496813
test-softpipe-gles31 2/4

00:05:01

passed #1496814
test-softpipe-gles31 3/4

00:04:01

passed #1496815
test-softpipe-gles31 4/4

00:05:35

passed #1496811
test-softpipe-gles3 2/2

00:05:55