editline(3) does not discuss return values for el_set()

[Ross Richardson]

editline(3) fails to mention the possible return
values of el_set().

Based on my superficial perusal of the source, it
looks like 0 on success, -1 otherwise.  Patch
(based on assumption that this is correct) attached.
--- editline.3.orig     Mon May 10 00:03:55 2010
+++ editline.3  Mon May 10 00:08:07 2010
@@ -194,6 +194,7 @@ parameters.
 .Fa op
 determines which parameter to set, and each operation has its
 own parameter list.
+Returns 0 on success, \-1 on failure.
 .Pp
 The following values for
 .Fa op