radv/winsys: fix resetting the number of padded IB words

The number of padded words is per IB, so it should be reset.

Found with Valgrind and dEQP-VK.api.command_buffers.record_many_draws*

Cc: 21.1 mesa-stable
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <!10376>
34 jobs for !10376 with radv_winsys_fix_sysmem_path in 9 minutes and 40 seconds (queued for 4 seconds)
latest detached
Status Job ID Name Coverage
  Sanity
passed sanity #9157045

00:00:16

 
  Container
passed arm_build #9157050
aarch64

00:00:23

passed windows_build_vs2019 #9157052
windows shell 1809 mesa

00:00:10

passed x86_build-base #9157047

00:00:24

passed x86_test-base #9157048

00:00:27

 
  Container 2
passed android_build #9157061

00:00:24

passed i386_build #9157056

00:00:23

passed kernel+rootfs_amd64 #9157067

00:00:25

passed kernel+rootfs_arm64 #9157069
aarch64

00:01:03

passed kernel+rootfs_armhf #9157071
aarch64

00:00:13

passed ppc64el_build #9157058

00:00:23

passed s390x_build #9157060

00:00:23

passed x86_build #9157054

00:00:24

passed x86_test-gl #9157063

00:00:25

passed x86_test-vk #9157065

00:00:21

 
  Meson X86 64
passed meson-clang #9157081

00:06:16

passed meson-clover #9157083

00:01:49

passed meson-clover-testing #9157077

00:00:50

passed meson-gallium #9157078

00:05:05

passed meson-release #9157080

00:02:57

passed meson-testing #9157073

00:01:48

passed meson-testing-asan #9157075

00:02:18

passed meson-vulkan #9157085

00:02:25

 
  Build Misc
passed arm_test #9157087

00:00:44

passed meson-android #9157089

00:01:21

passed meson-arm64 #9157093
aarch64

00:01:32

passed meson-arm64-asan #9157095
aarch64

00:03:39

passed meson-arm64-build-test #9157096
aarch64

00:01:56

passed meson-armhf #9157091
aarch64

00:01:33

passed meson-i386 #9157097

00:02:22

passed meson-mingw32-x86_64 #9157100

00:02:10

passed meson-ppc64el #9157099

00:01:05

passed meson-s390x #9157098
kvm

00:03:53

 
  Amd
passed radv-fossils #9157101

00:06:38