epoll.7: Reformat Q&A list

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man7/epoll.7

@@ -326,24 +326,20 @@ calling
 with
 .BR EPOLL_CTL_MOD .
 .SS Questions and answers
-.TP 4
-.B Q0
+.IP 0. 4
 What is the key used to distinguish the file descriptors registered in an
 .B epoll
 set?
-.TP
-.B A0
+.IP
 The key is the combination of the file descriptor number and
 the open file description
 (also known as an "open file handle",
 the kernel's internal representation of an open file).
-.TP
-.B Q1
+.IP 1.
 What happens if you register the same file descriptor on an
 .B epoll
 instance twice?
-.TP
-.B A1
+.IP
 You will probably get
 .BR EEXIST .
 However, it is possible to add a duplicate
@@ -373,37 +369,31 @@ This can be a useful technique for filtering events,
 if the duplicate file descriptors are registered with different
 .I events
 masks.
-.TP
-.B Q2
+.IP 2.
 Can two
 .B epoll
 instances wait for the same file descriptor?
 If so, are events reported to both
 .B epoll
 file descriptors?
-.TP
-.B A2
+.IP
 Yes, and events would be reported to both.
 However, careful programming may be needed to do this correctly.
-.TP
-.B Q3
+.IP 3.
 Is the
 .B epoll
 file descriptor itself poll/epoll/selectable?
-.TP
-.B A3
+.IP
 Yes.
 If an
 .B epoll
 file descriptor has events waiting, then it will
 indicate as being readable.
-.TP
-.B Q4
+.IP 4.
 What happens if one attempts to put an
 .B epoll
 file descriptor into its own file descriptor set?
-.TP
-.B A4
+.IP
 The
 .BR epoll_ctl (2)
 call fails
@@ -413,24 +403,20 @@ However, you can add an
 file descriptor inside another
 .B epoll
 file descriptor set.
-.TP
-.B Q5
+.IP 5.
 Can I send an
 .B epoll
 file descriptor over a UNIX domain socket to another process?
-.TP
-.B A5
+.IP
 Yes, but it does not make sense to do this, since the receiving process
 would not have copies of the file descriptors in the
 .B epoll
 set.
-.TP
-.B Q6
+.IP 6.
 Will closing a file descriptor cause it to be removed from all
 .B epoll
 sets automatically?
-.TP
-.B A6
+.IP
 Yes, but be aware of the following point.
 A file descriptor is a reference to an open file description (see
 .BR open (2)).
@@ -457,34 +443,28 @@ This means that even after a file descriptor that is part of an
 set has been closed,
 events may be reported for that file descriptor if other file
 descriptors referring to the same underlying file description remain open.
-.TP
-.B Q7
+.IP 7.
 If more than one event occurs between
 .BR epoll_wait (2)
 calls, are they combined or reported separately?
-.TP
-.B A7
+.IP
 They will be combined.
-.TP
-.B Q8
+.IP 8.
 Does an operation on a file descriptor affect the
 already collected but not yet reported events?
-.TP
-.B A8
+.IP
 You can do two operations on an existing file descriptor.
 Remove would be meaningless for
 this case.
 Modify will reread available I/O.
-.TP
-.B Q9
+.IP 9.
 Do I need to continuously read/write a file descriptor
 until
 .B EAGAIN
 when using the
 .B EPOLLET
 flag (edge-triggered behavior) ?
-.TP
-.B A9
+.IP
 Receiving an event from
 .BR epoll_wait (2)
 should suggest to you that such