all: remove unnecessary IError() casts

vlib/semver/range.v

@@ -87,16 +87,16 @@ fn parse_range(input string) ?Range {
 fn parse_comparator_set(input string) ?ComparatorSet {
 	raw_comparators := input.split(semver.comparator_sep)
 	if raw_comparators.len > 2 {
-		return IError(&InvalidComparatorFormatError{
+		return &InvalidComparatorFormatError{
 			msg: 'Invalid format of comparator set for input "$input"'
-		})
+		}
 	}
 	mut comparators := []Comparator{}
 	for raw_comp in raw_comparators {
 		c := parse_comparator(raw_comp) or {
-			return IError(&InvalidComparatorFormatError{
+			return &InvalidComparatorFormatError{
 				msg: 'Invalid comparator "$raw_comp" in input "$input"'
-			})
+			}
 		}
 		comparators << c
 	}

vlib/semver/semver.v

@@ -40,14 +40,12 @@ pub fn (err InvalidVersionFormatError) msg() string {
 // from returns a `Version` structure parsed from `input` `string`.
 pub fn from(input string) ?Version {
 	if input.len == 0 {
-		return IError(&EmptyInputError{})
+		return &EmptyInputError{}
 	}
 	raw_version := parse(input)
-	version := raw_version.validate() or {
-		return IError(&InvalidVersionFormatError{
-			input: input
-		})
-	}
+	version := raw_version.validate() or { return &InvalidVersionFormatError{
+		input: input
+	} }
 	return version
 }