Fix some gas warnings

Author: ccojocar

analyzer.go

@@ -102,7 +102,10 @@ func (gas *Analyzer) Process(packagePaths ...string) error {
 		AllowErrors: true,
 	}
 	for _, packagePath := range packagePaths {
-		abspath, _ := filepath.Abs(packagePath)
+		abspath, err := filepath.Abs(packagePath)
+		if err != nil {
+			return err
+		}
 		gas.logger.Println("Searching directory:", abspath)
 
 		basePackage, err := build.Default.ImportDir(packagePath, build.ImportComment)

issue.go

@@ -76,7 +76,7 @@ func codeSnippet(file *os.File, start int64, end int64, n ast.Node) (string, err
 	}
 
 	size := (int)(end - start) // Go bug, os.File.Read should return int64 ...
-	file.Seek(start, 0)
+	file.Seek(start, 0)        // #nosec
 
 	buf := make([]byte, size)
 	if nread, err := file.Read(buf); err != nil || nread != size {