fs/Path: rename RelativeFS() to Relative()

src/Mapper.cxx

@@ -98,7 +98,7 @@ map_fs_to_utf8(Path _path_fs)
 		if (music_dir_fs.IsNull())
 			return std::string();
 
-		path_fs = music_dir_fs.RelativeFS(path_fs);
+		path_fs = music_dir_fs.Relative(path_fs);
 		if (path_fs == nullptr || *path_fs == 0)
 			return std::string();
 	}

src/fs/AllocatedPath.cxx

@@ -62,7 +62,7 @@ AllocatedPath::ToUTF8() const
 }
 
 const char *
-AllocatedPath::RelativeFS(const char *other_fs) const
+AllocatedPath::Relative(const char *other_fs) const
 {
 	const size_t l = length();
 	if (memcmp(data(), other_fs, l) != 0)

src/fs/AllocatedPath.hxx

@@ -249,7 +249,7 @@ public:
 	 * nullptr on mismatch.
 	 */
 	gcc_pure
-	const char *RelativeFS(const char *other_fs) const;
+	const char *Relative(const char *other_fs) const;
 
 	/**
 	 * Chop trailing directory separators.

src/fs/Path.hxx

@@ -153,7 +153,7 @@ public:
 	 * nullptr on mismatch.
 	 */
 	gcc_pure
-	const_pointer RelativeFS(const_pointer other_fs) const {
+	const_pointer Relative(const_pointer other_fs) const {
 		return PathTraitsFS::Relative(value, other_fs);
 	}