Fix an extra newline in rendered std doc

Fixes #132564

Author: uellenberg

Diff for: library/std/src/lib.rs

@@ -32,9 +32,8 @@
 //!
 //! Once you are familiar with the contents of the standard library you may
 //! begin to find the verbosity of the prose distracting. At this stage in your
-//! development you may want to press the <code>
-//! <svg style="width:0.75rem;height:0.75rem" viewBox="0 0 12 12"
-//! stroke="currentColor" fill="none">
+//! development you may want to press the <code><svg style="width:0.75rem;height:0.75rem"
+//! viewBox="0 0 12 12" stroke="currentColor" fill="none">
 //! <path d="M2,2l4,4l4,-4M2,6l4,4l4,-4"/></svg> Summary</code> button near the
 //! top of the page to collapse it into a more skimmable view.
 //!