Revert "stailq.3, utmp.5, time_namespaces.7: srcfix: remove redundant .PP"

Do this in order to apply a better patch from Alex Colomar.

This reverts commit f7fc28f97a.

man3/stailq.3

@@ -256,6 +256,7 @@ macro.
 .\" .BR STAILQ_REMOVE (),
 .\" this macro does not traverse the entire tail queue.
 .SS Other features
+.PP
 .BR STAILQ_CONCAT ()
 concatenates the tail queue headed by
 .I head2

man5/utmp.5

@@ -237,6 +237,7 @@ removed, record-keeping is turned off.
 .br
 .I /var/log/wtmp
 .SH CONFORMING TO
+.PP
 POSIX.1 does not specify a
 .I utmp
 structure, but rather one named
@@ -288,6 +289,7 @@ Linux uses the BSD conventions for line contents, as documented above.
 .\" informative messages such as \fB"new time"\fP in the line field.
 System V has no \fIut_host\fP or \fIut_addr_v6\fP fields.
 .SH NOTES
+.PP
 Unlike various other
 systems, where utmp logging can be disabled by removing the file, utmp
 must always exist on Linux.

man7/time_namespaces.7

@@ -211,6 +211,7 @@ The motivation for adding time namespaces was to allow
 the monotonic and boot-time clocks to maintain consistent values
 during container migration and checkpoint/restore.
 .SH EXAMPLES
+.PP
 The following shell session demonstrates the operation of time namespaces.
 We begin by displaying the inode number of the time namespace
 of a shell in the initial time namespace: