Fix typo in deprecation lint message

Author: Xiretza

compiler/rustc_lint/messages.ftl

@@ -193,10 +193,10 @@ lint_confusable_identifier_pair = found both `{$existing_sym}` and `{$sym}` as i
     .other_use = other identifier used here
 
 lint_crate_name_in_cfg_attr_deprecated =
-    `crate_name` within an `#![cfg_attr] attribute is deprecated`
+    `crate_name` within an `#![cfg_attr]` attribute is deprecated
 
 lint_crate_type_in_cfg_attr_deprecated =
-    `crate_type` within an `#![cfg_attr] attribute is deprecated`
+    `crate_type` within an `#![cfg_attr]` attribute is deprecated
 
 lint_cstring_ptr = getting the inner pointer of a temporary `CString`
     .as_ptr_label = this pointer will be invalid

tests/ui/cfg/future-compat-crate-attributes-using-cfg_attr.stderr

@@ -1,4 +1,4 @@
-error: `crate_type` within an `#![cfg_attr] attribute is deprecated`
+error: `crate_type` within an `#![cfg_attr]` attribute is deprecated
   --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:4:18
    |
 LL | #![cfg_attr(foo, crate_type="bin")]
@@ -8,7 +8,7 @@ LL | #![cfg_attr(foo, crate_type="bin")]
    = note: for more information, see issue #91632 <https://github.com/rust-lang/rust/issues/91632>
    = note: `#[deny(deprecated_cfg_attr_crate_type_name)]` on by default
 
-error: `crate_name` within an `#![cfg_attr] attribute is deprecated`
+error: `crate_name` within an `#![cfg_attr]` attribute is deprecated
   --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:9:18
    |
 LL | #![cfg_attr(foo, crate_name="bar")]
@@ -17,7 +17,7 @@ LL | #![cfg_attr(foo, crate_name="bar")]
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #91632 <https://github.com/rust-lang/rust/issues/91632>
 
-error: `crate_type` within an `#![cfg_attr] attribute is deprecated`
+error: `crate_type` within an `#![cfg_attr]` attribute is deprecated
   --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:4:18
    |
 LL | #![cfg_attr(foo, crate_type="bin")]
@@ -27,7 +27,7 @@ LL | #![cfg_attr(foo, crate_type="bin")]
    = note: for more information, see issue #91632 <https://github.com/rust-lang/rust/issues/91632>
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
-error: `crate_name` within an `#![cfg_attr] attribute is deprecated`
+error: `crate_name` within an `#![cfg_attr]` attribute is deprecated
   --> $DIR/future-compat-crate-attributes-using-cfg_attr.rs:9:18
    |
 LL | #![cfg_attr(foo, crate_name="bar")]