Upgrade rust/crates/regex to 1.5.4

Test: make
Change-Id: I0eab39246dc2aea41a62c15661e350b490f06c1d
diff --git a/src/error.rs b/src/error.rs
index 1c32c85..3e0ec75 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -31,7 +31,7 @@
 }
 
 impl fmt::Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
             Error::Syntax(ref err) => err.fmt(f),
             Error::CompiledTooBig(limit) => write!(
@@ -49,7 +49,7 @@
 // but the `Syntax` variant is already storing a `String` anyway, so we might
 // as well format it nicely.
 impl fmt::Debug for Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
             Error::Syntax(ref err) => {
                 let hr: String = repeat('~').take(79).collect();