scripts: squash a -Wmaybe-uninitialized

Closes: #968
Approved by: cgwalters

ci/build-check.sh

@@ -14,7 +14,7 @@ git clean -dfx
 
 # And now a clang build to find unused variables
 export CC=clang
-export CFLAGS='-Werror=unused-variable'
+export CFLAGS='-Werror=unused-variable -Werror=maybe-uninitialized'
 build_default
 # don't actually run the tests, just compile them
 /usr/bin/make check TESTS=

src/libpriv/rpmostree-scripts.c

@@ -488,6 +488,8 @@ rpmostree_script_run_sync (DnfPackage    *pkg,
     case RPMOSTREE_SCRIPT_POSTTRANS:
       scriptkind = &posttrans_script;
       break;
+    default:
+      g_assert_not_reached ();
     }
 
   gboolean did_run = FALSE;