anv: fix memory allocation error handling

Reported by Coverity.

Fixes: 0a7224f3 ("anv: group as many command buffers into a single execbuf")
Signed-off-by: Marcin Ślusarz <marcin.slusarz@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <!9596>
35 jobs for !9596 with anv-alloc in 3 minutes and 43 seconds (queued for 2 seconds)
latest detached
Status Job ID Name Coverage
  Sanity
passed #7989775
sanity

00:00:10

 
  Container
passed #7989778
aarch64
arm_build

00:00:18

passed #7989779
arm_test-base

00:00:16

passed #7989780
windows shell 1809 mesa
windows_build_vs2019

00:00:08

passed #7989776
x86_build-base

00:00:14

passed #7989777
x86_test-base

00:00:13

 
  Container 2
passed #7989788
android_build

00:00:14

passed #7989791
arm64_test

00:00:15

passed #7989792
armhf_test

00:00:14

passed #7989785
i386_build

00:00:14

passed #7989781
kernel+rootfs_amd64

00:00:10

passed #7989782
aarch64
kernel+rootfs_arm64

00:00:51

passed #7989783
aarch64
kernel+rootfs_armhf

00:00:10

passed #7989786
ppc64el_build

00:00:13

passed #7989787
s390x_build

00:00:14

passed #7989784
x86_build

00:00:18

passed #7989789
x86_test-gl

00:00:18

passed #7989790
x86_test-vk

00:00:14

 
  Meson X86 64
passed #7989798
meson-clang

00:01:48

passed #7989799
meson-clover

00:02:31

passed #7989795
meson-clover-testing

00:01:12

passed #7989796
gstreamer
meson-gallium

00:02:05

passed #7989797
meson-release

00:01:14

passed #7989793
meson-testing

00:01:46

passed #7989794
meson-testing-asan

00:02:26

passed #7989800
meson-vulkan

00:01:39

 
  Build Misc
passed #7989801
meson-android

00:01:18

passed #7989803
aarch64
meson-arm64

00:01:33

passed #7989804
aarch64
meson-arm64-asan

00:03:08

passed #7989805
aarch64
meson-arm64-build-test

00:01:28

passed #7989802
aarch64
meson-armhf

00:01:30

passed #7989806
meson-i386

00:01:52

passed #7989809
meson-mingw32-x86_64

00:01:50

passed #7989808
kvm
meson-ppc64el

00:02:22

passed #7989807
kvm
meson-s390x

00:02:36