[gparted] Stop parallelising make distcheck in GitLab CI test jobs (!6)

[Curtis Gedak <gedakc src gnome org>]

commit 112f1d3e67ae1231ad179c0ae278e1397f803d16
Author: Mike Fleetwood <mike fleetwood googlemail com>
Date:   Fri Jul 6 11:28:55 2018 +0100

    Stop parallelising make distcheck in GitLab CI test jobs (!6)
    
    Unfortunately parallelising 'make distcheck' causes it to fail like
    this:
    
        $ nproc=`grep -c '^processor' /proc/cpuinfo` || nproc=1
        $ echo nproc=$nproc
        nproc=8
        ...
        $ make -j $nproc distcheck
        ...
        make[1]: Entering directory '/builds/mfleetwo/gparted/gparted-0.31.0-git/_build/sub'
        ERROR: files left after uninstall:
        ./share/icons/hicolor/icon-theme.cache
        Makefile:896: recipe for target 'distuninstallcheck' failed
        make[1]: Leaving directory '/builds/mfleetwo/gparted/gparted-0.31.0-git/_build/sub'
        make[1]: *** [distuninstallcheck] Error 1
        make: *** [distcheck] Error 1
        Makefile:840: recipe for target 'distcheck' failed
        ERROR: Job failed: exit code 1
    
    Therefore go back to serial 'make distcheck'.
    
    Closes !6 - Reduce the time taken by the GitLab CI jobs

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 33d78d66..a3444ff8 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -39,7 +39,7 @@ stages:
     # Exclude specific unit test which fails without /dev/disk in Docker images.
     - export GTEST_FILTER='-BlockSpecialTest.NamedBlockSpecialObjectBySymlinkMatches'
     - make check
-    - make -j $nproc distcheck
+    - make distcheck
 
 # Check GParted can be built and installed on CentOS and Ubuntu.
 centos_build: