Removed the two previously added errors.

Replaced `ZeroMountPointsFound` and `CantOpenMountPointsFile` with
`panic!` after coming across https://lukaskalbertodt.github.io/2019/11/14/thoughts-on-error-handling-in-rust.html
and reading http://joeduffyblog.com/2016/02/07/the-error-model/

src/lib.rs

@@ -99,14 +99,6 @@ pub enum ErrorKind {
     /// obtained with `HRESULT_FROM_WIN32(GetLastError())`
     PlatformApi { function_name: &'static str, code: Option<i32> },
 
-    /// This is a Linux specific Error that occures when neither '/proc/mounts' nor '/etc/mtab'
-    /// could be opened. This may happen during `remove`, `remove_all`, or `list`
-    CantOpenMountPointsFile,
-
-    /// This is a Linux specific Error that occurs when a mount points file could be opened
-    /// but the very first call to `getmntent` returned NULL.
-    ZeroMountPointsFound,
-
     /// Error while canonicalizing path.
     ///
     /// The `source()` function of the `Error` will return a reference to an `std::io::Error`.

src/linux.rs

@@ -583,7 +583,6 @@ fn home_trash() -> Result<PathBuf, Error> {
             return Ok(home_path.join(".local/share/Trash").into());
         }
     }
-
     panic!("Neither the XDG_DATA_HOME nor the HOME environment variable was found");
 }
 
@@ -604,7 +603,7 @@ fn get_mount_points() -> Result<Vec<MountPoint>, Error> {
         file = unsafe { libc::fopen(mtab_path.as_c_str().as_ptr(), read_arg.as_c_str().as_ptr()) };
     }
     if file == std::ptr::null_mut() {
-        return Err(Error::kind_only(ErrorKind::CantOpenMountPointsFile));
+        panic!("Neither '/proc/mounts' nor '/etc/mtab' could be opened.");
     }
     defer! {{ unsafe { libc::fclose(file); } }}
     let mut result = Vec::new();
@@ -627,9 +626,9 @@ fn get_mount_points() -> Result<Vec<MountPoint>, Error> {
         result.push(mount_point);
     }
     if result.len() == 0 {
-        // If the mountpoints file could be opened but no mountpoints are found
-        // there possibly is a serious issue
-        return Err(Error::kind_only(ErrorKind::ZeroMountPointsFound));
+        panic!(
+            "A mount points file could be opened but the first call to `getmntent` returned NULL."
+        );
     }
     Ok(result)
 }