scripts/text2pod.pl: Escape left brace

Latest perl now deprecates "{" literal in regex and print warnings like
"unescaped left brace in regex is deprecated".  Add escapes to keep it
happy.

Signed-off-by: Fam Zheng <famz@redhat.com>

Message-Id: <1445326726-16031-1-git-send-email-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/scripts/texi2pod.pl b/scripts/texi2pod.pl
index 94097fb..8767662 100755
--- a/scripts/texi2pod.pl
+++ b/scripts/texi2pod.pl
@@ -317,7 +317,7 @@
 	@columns = ();
 	for $column (split (/\s*\@tab\s*/, $1)) {
 	    # @strong{...} is used a @headitem work-alike
-	    $column =~ s/^\@strong{(.*)}$/$1/;
+	    $column =~ s/^\@strong\{(.*)\}$/$1/;
 	    push @columns, $column;
 	}
 	$_ = "\n=item ".join (" : ", @columns)."\n";