Fix undesired LF in literals

[idodeclare]

Please consider for integration this patch to fix some undesired LF in literal elements.

1. DTrace — Structs chapter

Below shows how without this patch, a dtrace command is spaced oddly:

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2. Memory and Thread Placement Optimization — MPO Observability Tools chapter

Below shows how without this patch, a "start lgroup ID" item is spaced oddly:

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3. ZFS File System — introduction

Below shows how without this patch, a zfs rename command is spaced oddly:

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There were some instances of undesired LF in literal elements that weren't rendering oddly because they were early enough within the line; I cleaned them up anyway so that a code pattern search didn't find them anymore.

--CF

[rmustacc]

Thanks for this and #110 @idodeclare. I'll be reviewing these both over the next day or two.