refactor/polish ~ fix cargo clippy complaints (deprecated std::error::Error::description)

src/cat/Cargo.toml

@@ -9,7 +9,7 @@ name = "uu_cat"
 path = "cat.rs"
 
 [dependencies]
-quick-error = "1.2.2"
+quick-error = "1.2.3"
 
 [dependencies.uucore]
 version = "0.0.1"

src/cp/Cargo.toml

@@ -16,7 +16,7 @@ getopts = "0.2.18"
 libc = "0.2.42"
 walkdir = "2.2.8"
 clap = "2.32.0"
-quick-error = "1.2.2"
+quick-error = "1.2.3"
 filetime = "0.2"
 
 [dependencies.uucore]

src/stat/fsext.rs

@@ -141,7 +141,6 @@ pub fn pretty_access(mode: mode_t) -> String {
 
 use std::borrow::Cow;
 use std::convert::{AsRef, From};
-use std::error::Error;
 use std::ffi::CString;
 use std::io::Error as IOError;
 use std::mem;
@@ -290,7 +289,7 @@ where
                 }
             }
         }
-        Err(e) => Err(e.description().to_owned()),
+        Err(e) => Err(e.to_string()),
     }
 }
 

src/tail/tail.rs

@@ -149,7 +149,7 @@ pub fn uumain(args: Vec<String>) -> i32 {
             match parse_size(slice) {
                 Ok(m) => settings.mode = FilterMode::Lines(m, b'\n'),
                 Err(e) => {
-                    show_error!("{}", e.description());
+                    show_error!("{}", e.to_string());
                     return 1;
                 }
             }
@@ -164,7 +164,7 @@ pub fn uumain(args: Vec<String>) -> i32 {
                 match parse_size(slice) {
                     Ok(m) => settings.mode = FilterMode::Bytes(m),
                     Err(e) => {
-                        show_error!("{}", e.description());
+                        show_error!("{}", e.to_string());
                         return 1;
                     }
                 }
@@ -245,7 +245,7 @@ impl Error for ParseSizeErr {
 
 impl fmt::Display for ParseSizeErr {
     fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-        write!(f, "{}", Error::description(self))
+        write!(f, "{}", self.to_string())
     }
 }