fix trivial typo in manpage

Fix small typo as reported by Kent Baxley <[email protected]> in Red Hat Bug 489941 - tiny typo in blktrace manpage

---

Index: blktrace/doc/blktrace.8 =================================--- blktrace.orig/doc/blktrace.8 +++ blktrace/doc/blktrace.8
@@ -169,7 +169,7 @@ line options.
.RS
\fIbarrier\fR: barrier attribute
.br
-\fIcomplete\fR: completed} by driver
+\fIcomplete\fR: completed by driver
.br
\fIfs\fR: requests
.br