Coding-style: remove superfluous parentheses

Mostly replace "return (expression);" by "return expression;" and one
case of "function((parameter))" by "function(parameter)".

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

core/exif.cpp

@@ -897,6 +897,6 @@ time_t easyexif::EXIFInfo::epoch()
 	tm.tm_hour = hour;
 	tm.tm_min = min;
 	tm.tm_sec = sec;
-	return (utc_mktime(&tm));
+	return utc_mktime(&tm);
 }