Use correct function to free allocated mem

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%402068

src/cdrom/linux/SDL_syscdrom.c

@@ -222,7 +222,7 @@ CheckMounts(const char *mtab)
             if (SDL_strcmp(mnt_type, MNTTYPE_SUPER) == 0) {
                 tmp = SDL_strstr(mntent->mnt_opts, "fs=");
                 if (tmp) {
-                    SDL_free(mnt_type);
+                    SDL_stack_free(mnt_type);
                     mnt_type = SDL_strdup(tmp + SDL_strlen("fs="));
                     if (mnt_type) {
                         tmp = SDL_strchr(mnt_type, ',');
@@ -233,7 +233,7 @@ CheckMounts(const char *mtab)
                 }
                 tmp = SDL_strstr(mntent->mnt_opts, "dev=");
                 if (tmp) {
-                    SDL_free(mnt_dev);
+                    SDL_stack_free(mnt_dev);
                     mnt_dev = SDL_strdup(tmp + SDL_strlen("dev="));
                     if (mnt_dev) {
                         tmp = SDL_strchr(mnt_dev, ',');