Merge rust-bitcoin#678: schnorr: Change verify_schnorr error return type

adee34f schnorr: Change verify_schnorr error return type (Steven Roose)

Pull request description:

  Bumped into this.

ACKs for top commit:
  Kixunil:
    ACK adee34f
  tcharding:
    ACK adee34f
  apoelstra:
    ACK adee34f

Tree-SHA512: 7ddad93fc69e36d7d33b54526b7c108df9fc69e6153eb583a69eca840c3bd095bcabe03c32ad21577e0fe1a12f1d191d7f5b7edd722fd20ecc200a30c8ee4d25

src/schnorr.rs

@@ -181,7 +181,7 @@ impl<C: Verification> Secp256k1<C> {
             if ret == 1 {
                 Ok(())
             } else {
-                Err(Error::InvalidSignature)
+                Err(Error::IncorrectSignature)
             }
         }
     }