fanotify_mark.2: Minor wording fixes

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

man2/fanotify_mark.2

@@ -70,7 +70,7 @@ must be nonempty or the error
 will occur.
 .TP
 .B FAN_MARK_FLUSH
-Remove either all mount or non-mount marks from the fanotify group.
+Remove either all mount or all non-mount marks from the fanotify group.
 If
 .I flag
 contains
@@ -89,8 +89,8 @@ the call fails with the error
 .BR EINVAL .
 .PP
 In addition,
-.I flags
-may contain zero or more of the following:
+zero or more of the following values may be ORed into
+.IR flags :
 .TP
 .B FAN_MARK_DONT_FOLLOW
 If
@@ -131,7 +131,7 @@ the ignore mask is cleared when a modify event occurs
 for the ignored file or directory.
 .PP
 .I mask
-defines which events shall be listened to (or which shall be ignored).
+defines which events shall be listened for (or which shall be ignored).
 It is a bit mask composed of the following values:
 .TP
 .B FAN_ACCESS
@@ -166,7 +166,7 @@ or
 is required.
 .TP
 .B FAN_ONDIR
-Events for directories shall be created, for example when
+Create events for directories\(emfor example, when
 .BR opendir (2),
 .BR readdir (2)
 (but see BUGS), and
@@ -276,17 +276,16 @@ which is not marked.
 The necessary memory could not be allocated.
 .TP
 .B ENOSPC
-The number of marks exceeds the limit of 8192 and
+The number of marks exceeds the limit of 8192 and the
 .B FAN_UNLIMITED_MARKS
-was not specified in the call to
+flag was not specified when the fanotify file descriptor was created with
 .BR fanotify_init (2).
 .TP
 .B ENOSYS
 This kernel does not implement
 .BR fanotify_mark (). 
-To make the fanotify API available,
-.B CONFIG_FANOTIFY
-has to be enabled in the Linux configuration.
+The fanotify API is available only if the kernel was configured with
+.BR CONFIG_FANOTIFY .
 .TP
 .B ENOTDIR
 .I flags