CL-USER> (defun dereturnify (string)
           (let ((string (cl-ppcre:regex-replace-all "\\\\r$" string "")))
             (cl-ppcre:regex-replace-all "\\\\r\\n" string (string #\Newline))))
DERETURNIFY

CL-USER> *string*
"asach@ellis:~$ avidemux_2.7.4.appImage \\r
Feetype vesion 2.9.1\\r"

CL-USER> (dereturnify *string*)
"asach@ellis:~$ avidemux_2.7.4.appImage 
Feetype vesion 2.9.1"
T