MFC r315772:

tmpfs(5): fix mdoc warnings

- Delete trailing whitespace
- Sort SEE ALSO order: mmap(2)'s Xr should come before nmount(2)'s Xr.

MFC r312649:
Document mount option "nonc" for tmpfs.

MFC r312423:
Refresh tmpfs(5) man page.

MFC r312648:
Editing and clarifications for tmpfs(5).

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Update the bugs section. We don't consider tmpfs as experimental,
though we do not claim to support all mount options equally well.

Approved by: delphij@
MFC after: 3 days

Xref mdmfs(8).

Improve descriptions for tmpfs mount options. The descriptions have
been mostly obtained from NetBSD mount_tmpfs(8) manual page.

Obtained from: NetBSD
Discussed with: delphij

Remove clause 3 from my license.

Bump .Dd for r203164.

Approved by: trasz (mentor)

Add "maxfilesize" mount option for tmpfs to allow specifying the
maximum file size limit. Default is UINT64_MAX when the option is
not specified. It was useless to set the limit to the total amount of
memory and swap in the system.

Use tmpfs_mem_info() rather than get_swpgtotal() in tmpfs_mount() to
check if there is enough memory available.

Remove now unused get_swpgtotal().

Reviewed by: Gleb Kurtsou
Approved by: trasz (mentor)

Add a missing .El.

Founded by: make manlint

Document more tmpfs mount options that are already
available.

PR: 124488
Submitted by: gahr

Remove some stuff I accidently left in the previous commit.

Complete SYNOPSIS and some cleanup.

Add a manual page for tmpfs(5).