iris: use normal initializer for samplerview creation

atomics here generate a huge amount of overhead (20% of all CPU time in pbobench)
and aren't actually needed
36 jobs for !10634 with iris-overheadminusminus in 9 seconds (queued for 6 seconds)
latest detached
Status Job ID Name Coverage
  Sanity
passed #9468620
sanity

00:00:09

 
  Container
manual #9468623
aarch64 manual
arm_build
manual #9468624
windows shell 1809 mesa manual
windows_build_vs2019
manual #9468621
manual
x86_build-base
manual #9468622
manual
x86_test-base
 
  Container 2
created #9468629
android_build
created #9468626
i386_build
created #9468632
kernel+rootfs_amd64
created #9468633
aarch64
kernel+rootfs_arm64
created #9468634
aarch64
kernel+rootfs_armhf
created #9468627
ppc64el_build
created #9468628
s390x_build
created #9468625
x86_build
created #9468630
x86_test-gl
created #9468631
x86_test-vk
 
  Meson X86 64
created #9468640
meson-clang
created #9468641
meson-clover
created #9468637
meson-clover-testing
created #9468638
meson-gallium
created #9468639
meson-release
created #9468635
meson-testing
created #9468636
meson-testing-asan
created #9468642
meson-vulkan
 
  Build Misc
created #9468643
arm_test
created #9468644
meson-android
created #9468646
aarch64
meson-arm64
created #9468647
aarch64
meson-arm64-asan
created #9468648
aarch64
meson-arm64-build-test
created #9468645
aarch64
meson-armhf
created #9468649
meson-i386
created #9468652
meson-mingw32-x86_64
created #9468651
meson-ppc64el
created #9468650
kvm
meson-s390x
 
  Intel
created #9468655
mesa-ci-aarch64-lava-collabora manual
iris-amly-traces:amd64
created #9468653
mesa-ci-aarch64-lava-collabora manual
iris-apl-traces:amd64
created #9468654
mesa-ci-aarch64-lava-collabora manual
iris-glk-traces:amd64