poll.2: ffix

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

man2/poll.2

@@ -157,7 +157,6 @@ The bits that may be set/returned in
 and
 .I revents
 are defined in \fI<poll.h>\fP:
-.RS
 .TP
 .B POLLIN
 There is data to read.
@@ -206,13 +205,11 @@ not open (only returned in
 .IR revents ;
 ignored in
 .IR events ).
-.RE
 .PP
 When compiling with
 .B _XOPEN_SOURCE
 defined, one also has the following,
 which convey no further information beyond the bits listed above:
-.RS
 .TP
 .B POLLRDNORM
 Equivalent to
@@ -228,7 +225,6 @@ Equivalent to
 .TP
 .B POLLWRBAND
 Priority data may be written.
-.RE
 .PP
 Linux also knows about, but does not use
 .BR POLLMSG .