Merge #35: Avoid redundant std::move

2352178 Avoid redundant std::move (Pieter Wuille)

Pull request description:

  I added this move initially because I believed the NVRO optimization didn't apply here (return type differs from variable type being returned). However, upon closer inspection this is not necessary: see "Automatic move from local variables and parameters" on https://en.cppreference.com/w/cpp/language/return, which states that even if the type differs, move-returning will be done if available.

ACKs for top commit:
  jnewbery:
    ACK 2352178
  theuni:
    ACK 2352178

Tree-SHA512: 6f8b8a3c1843d1b01df0e62983d918e6c08030a2aa74535c45a7cdc3a769322423fdfb8f2832043f06423427874fc5b90011cda5dde1c127c852ae4df02fdc74

Author: sipa

include/minisketch.h

@@ -303,7 +303,7 @@ class Minisketch
         ssize_t ret = minisketch_decode(m_minisketch.get(), max_elements, result.data());
         if (ret == -1) return {};
         result.resize(ret);
-        return std::move(result);
+        return result;
     }
 
     /** C++17 only: similar to Decode(), but with specified false positive probability. */