Remove duplicate sentence from alarm() doc.
(backport from rev. 56143)
diff --git a/Doc/lib/libsignal.tex b/Doc/lib/libsignal.tex
index cfdb4dd..e98aa90 100644
--- a/Doc/lib/libsignal.tex
+++ b/Doc/lib/libsignal.tex
@@ -101,8 +101,7 @@
be scheduled at any time). The returned value is then the number of
seconds before any previously set alarm was to have been delivered.
If \var{time} is zero, no alarm is scheduled, and any scheduled
- alarm is canceled. The return value is the number of seconds
- remaining before a previously scheduled alarm. If the return value
+ alarm is canceled. If the return value
is zero, no alarm is currently scheduled. (See the \UNIX{} man page
\manpage{alarm}{2}.)
Availability: \UNIX.