You will be fine and your return will be mailed in on-time if postmarked before the filing deadline.
According to the IRS:
Mailing an income tax return to the wrong Internal Revenue Service Center or otherwise misaddressing the return could delay the processing of the return and any refund.
So if you mail it to the wrong address, it slows things down, but there's no penalty. It will be forwarded to the right address.
More details can be found here https://www.irs.gov/irb/2007-15_IRB/ar09.html
