searcher: revert big-endian patch

This undoes the patch to stop using bytecount on big-endian
architectures. In particular, we bump our bytecount dependency to the
latest release, which has a fix.

This reverts commit a4868b8835.

Fixes #1144 (again), Closes #1194

grep-searcher/src/lines.rs

@@ -109,17 +109,10 @@ impl LineStep {
 }
 
 /// Count the number of occurrences of `line_term` in `bytes`.
-#[cfg(target_endian = "little")]
 pub fn count(bytes: &[u8], line_term: u8) -> u64 {
     bytecount::count(bytes, line_term) as u64
 }
 
-/// Count the number of occurrences of `line_term` in `bytes`.
-#[cfg(target_endian = "big")]
-pub fn count(bytes: &[u8], line_term: u8) -> u64 {
-    bytecount::naive_count(bytes, line_term) as u64
-}
-
 /// Given a line that possibly ends with a terminator, return that line without
 /// the terminator.
 #[inline(always)]