futex.2: ffix: Separate text about ignored arguments into individual paragraphs

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

man2/futex.2

@@ -125,6 +125,7 @@ blocking interval may overrun by a small amount.)
 If
 .I timeout
 is NULL, the call blocks indefinitely.
+
 The arguments
 .I uaddr2
 and
@@ -143,6 +144,7 @@ operation.
 This operation wakes at most \fIval\fP
 processes waiting on this futex address (i.e., inside
 .BR FUTEX_WAIT ).
+
 The arguments
 .IR timeout ,
 .I uaddr2
@@ -165,6 +167,7 @@ If another process executes a
 the process will receive the signal number that was passed in
 .IR val .
 The calling process must close the returned file descriptor after use.
+
 The arguments
 .IR timeout ,
 .I uaddr2
@@ -190,6 +193,7 @@ This call wakes up
 .I val
 processes, and requeues all other waiters on the futex at address
 .IR uaddr2 .
+
 The arguments
 .I timeout
 and
@@ -210,6 +214,7 @@ still contains the value
 .IR val3 .
 If not, the operation fails with the error
 .BR EAGAIN .
+
 The argument
 .I timeout
 is ignored.