rm: Remove -i from usage and manpage

We do not support it so do not lie to the user.

rm.1

@@ -1,4 +1,4 @@
-.Dd January 30, 2015
+.Dd February 19, 2015
 .Dt RM 1
 .Os sbase
 .Sh NAME
@@ -6,7 +6,7 @@
 .Nd remove directory entries
 .Sh SYNOPSIS
 .Nm
-.Op Fl f | Fl i
+.Op Fl f
 .Op Fl Rr
 .Ar file ...
 .Sh DESCRIPTION
@@ -22,8 +22,8 @@ or
 is specified.
 .Sh OPTIONS
 .Bl -tag -width Ds
-.It Fl f | Fl i
-Do not prompt | Prompt before removing
+.It Fl f
+Do not prompt before removing.
 .Ar file .
 In the former case, do not report when
 .Ar file