[PATCH -perfbook 1/5] intro: Use "VerbatimU" env for non-float code snippet

Let's use our custom environment for this sort of snippet.

Signed-off-by: Akira Yokosawa <[email protected]>
---
 intro/intro.tex | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/intro/intro.tex b/intro/intro.tex
index 7def3d9b..fc0f97e2 100644
--- a/intro/intro.tex
+++ b/intro/intro.tex
@@ -1200,13 +1200,11 @@ adapting systems to run on multi-core systems.
 For example, consider the following hash-table API that might be used
 in sequential code:
 
-\begin{quote}
-\begin{verbatim}
+\begin{VerbatimU}
 int hash_add(struct htab *htp);
 int hash_del(int key);
 struct htab *hash_lookup(int key);
-\end{verbatim}
-\end{quote}
+\end{VerbatimU}
 
 Here, \co{hash_add()} and \co{hash_del()} both return the exact number
 of elements in the hash table after the operation completes, or -1
-- 
2.43.0