qemu: fix error message on directory creation

Minor copy-and-paste bug present since commit 462c74c3, in Apr 2010.
Signed-off-by: NEric Blake <eblake@redhat.com>

src/qemu/qemu_driver.c

@@ -656,7 +656,7 @@ qemuStateInitialize(bool privileged,
         goto error;
     }
     if (virFileMakePath(cfg->snapshotDir) < 0) {
-        virReportSystemError(errno, _("Failed to create save dir %s"),
+        virReportSystemError(errno, _("Failed to create snapshot dir %s"),
                              cfg->snapshotDir);
         goto error;
     }