Remove obsolete bits about maximum number of file systems.

NMOUNT has gone together with static mount table in 4.3BSD-Reno.

MFC after:	1 week

lib/libc/sys/mount.2

@@ -28,7 +28,7 @@
 .\"     @(#)mount.2	8.3 (Berkeley) 5/24/95
 .\" $FreeBSD$
 .\"
-.Dd January 26, 2010
+.Dd April 13, 2015
 .Dt MOUNT 2
 .Os
 .Sh NAME
@@ -351,11 +351,6 @@ The
 argument
 points outside the process's allocated address space.
 .El
-.Pp
-A
-.Em ufs
-mount can also fail if the maximum number of file systems are currently
-mounted.
 .Sh SEE ALSO
 .Xr lsvfs 1 ,
 .Xr mksnap_ffs 8 ,