build: fix meson warning about path separator in target

Fix the following:

 WARNING: Target "nm-utils/tests/test-shared-general" has a path
 separator in its name.  This is not supported, it can cause
 unexpected failures and will become a hard error in the future.

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/issues/217

shared/meson.build

@@ -330,24 +330,6 @@ libnm_systemd_shared_no_logging_dep = declare_dependency(
   ],
 )
 
-###############################################################################
+if enable_tests
-
+  subdir('nm-utils/tests')
-exe = executable(
+endif
-    'nm-utils/tests/test-shared-general',
-    [ 'nm-utils/tests/test-shared-general.c' ],
-    c_args: [
-        '-DNETWORKMANAGER_COMPILATION_TEST',
-        '-DNETWORKMANAGER_COMPILATION=(NM_NETWORKMANAGER_COMPILATION_GLIB|NM_NETWORKMANAGER_COMPILATION_WITH_GLIB_I18N_PROG)',
-    ],
-    dependencies: [
-        shared_nm_glib_aux_dep,
-        libnm_systemd_shared_no_logging_dep,
-        shared_c_siphash_dep,
-    ],
-)
-
-test(
-    'shared/nm-utils/tests/test-shared-general',
-    test_script,
-    args: test_args + [exe.full_path()]
-)

shared/nm-utils/tests/meson.build

@@ -0,0 +1,22 @@
+test_unit = 'test-shared-general'
+
+exe = executable(
+  test_unit,
+  test_unit + '.c',
+  c_args: [
+    '-DNETWORKMANAGER_COMPILATION_TEST',
+    '-DNETWORKMANAGER_COMPILATION=(NM_NETWORKMANAGER_COMPILATION_GLIB|NM_NETWORKMANAGER_COMPILATION_WITH_GLIB_I18N_PROG)',
+  ],
+  dependencies: [
+    shared_nm_glib_aux_dep,
+    libnm_systemd_shared_no_logging_dep,
+    shared_c_siphash_dep,
+  ],
+)
+
+test(
+  'shared/nm-utils/' + test_unit,
+  test_script,
+  args: test_args + [exe.full_path()],
+  timeout: default_test_timeout,
+)