fuzz: Fix leak when assembling datadir path string

We freed the string containing the final datadir path, but did not free
the path to the executable's directory that we get from
g_path_get_dirname(). Fix that.

Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Message-Id: <20200717163523.1591-1-alxndr@bu.edu>
Signed-off-by: Thomas Huth <thuth@redhat.com>

tests/qtest/fuzz/fuzz.c

@@ -143,7 +143,7 @@ int LLVMFuzzerInitialize(int *argc, char ***argv, char ***envp)
 {
 
     char *target_name;
-    char *dir;
+    char *bindir, *datadir;
     bool serialize = false;
 
     /* Initialize qgraph and modules */
@@ -164,11 +164,13 @@ int LLVMFuzzerInitialize(int *argc, char ***argv, char ***envp)
          * location of the executable. Using this we add exec_dir/pc-bios to
          * the datadirs.
          */
-        dir = g_build_filename(g_path_get_dirname(**argv), "pc-bios", NULL);
-        if (g_file_test(dir, G_FILE_TEST_IS_DIR)) {
-            qemu_add_data_dir(dir);
+        bindir = g_path_get_dirname(**argv);
+        datadir = g_build_filename(bindir, "pc-bios", NULL);
+        g_free(bindir);
+        if (g_file_test(datadir, G_FILE_TEST_IS_DIR)) {
+            qemu_add_data_dir(datadir);
         }
-        g_free(dir);
+        g_free(datadir);
     } else if (*argc > 1) {  /* The target is specified as an argument */
         target_name = (*argv)[1];
         if (!strstr(target_name, "--fuzz-target=")) {