Check help message in the test

Author: reddevilmidzy

tests/ui/error-codes/E0050.rs

@@ -8,8 +8,11 @@ struct Bar;
 
 impl Foo for Bar {
     fn foo(&self) -> bool { true } //~ ERROR E0050
+    //~| HELP: modify the signature to match the trait definition
     fn bar(&self) { } //~ ERROR E0050
+    //~| HELP: modify the signature to match the trait definition
     fn less(&self, x: u8, y: u8, z: u8) { } //~ ERROR E0050
+    //~| HELP: modify the signature to match the trait definition
 }
 
 fn main() {

tests/ui/error-codes/E0050.stderr

@@ -13,7 +13,7 @@ LL |     fn foo(&self, x: u8) -> bool { true }
    |                 +++++++
 
 error[E0050]: method `bar` has 1 parameter but the declaration in trait `Foo::bar` has 4
-  --> $DIR/E0050.rs:11:12
+  --> $DIR/E0050.rs:12:12
    |
 LL |     fn bar(&self, x: u8, y: u8, z: u8);
    |            -------------------------- trait requires 4 parameters
@@ -27,7 +27,7 @@ LL |     fn bar(&self, x: u8, y: u8, z: u8) { }
    |                 +++++++++++++++++++++
 
 error[E0050]: method `less` has 4 parameters but the declaration in trait `Foo::less` has 1
-  --> $DIR/E0050.rs:12:13
+  --> $DIR/E0050.rs:14:13
    |
 LL |     fn less(&self);
    |             ----- trait requires 1 parameter