Update rsautl.pod for typo

Fixes the typo
CLA: trivial
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4354)

doc/man1/rsautl.pod

@@ -130,7 +130,7 @@ Recover the signed data
 
 Examine the raw signed data:
 
- openssl rsautl -verify -in file -inkey key.pem -raw -hexdump
+ openssl rsautl -verify -in sig -inkey key.pem -raw -hexdump
 
  0000 - 00 01 ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................
  0010 - ff ff ff ff ff ff ff ff-ff ff ff ff ff ff ff ff   ................