mesa: use a correct function return type

v2: standard 'bool' can be used
     ( Eric Engestrom <eric.engestrom@intel.com> )

Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
Signed-off-by: Andrii Simiklit <andrii.simiklit@globallogic.com>
10 jobs for !1179 with mesa_correct_f_ret_type in 9 minutes and 6 seconds (queued for 1 second)
latest detached
Status Job ID Name Coverage
  Containers Build
passed #384380
debian

00:00:17

 
  Build+Test
passed #384382
meson-clang

00:08:47

passed #384386
meson-clover

00:08:21

passed #384385
meson-main

00:05:48

passed #384381
meson-swr-glvnd

00:04:46

passed #384387
meson-vulkan

00:01:51

passed #384389
scons-llvm

00:04:27

passed #384388
scons-nollvm

00:02:22

passed #384383
scons-swr

00:02:44

passed #384384
scons-win64

00:06:09