cpuset.7, initrd.7, pipe.7, symlink.2: wfix: make "filesystem" one word

More s/file system/filesystem/ but multiline (see 9ee4a2b6)

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

man2/symlink.2

@@ -99,8 +99,8 @@ did not allow search permission.
 .TP
 .B EDQUOT
 The user's quota of resources on the filesystem has been exhausted.
-The resources could be inodes or disk blocks, depending on the file
-system implementation.
+The resources could be inodes or disk blocks, depending on the filesystem
+implementation.
 .TP
 .B EEXIST
 .I newpath

man4/initrd.4

@@ -353,8 +353,8 @@ sets
 .IR /proc/sys/kernel/real-root-dev ,
 unmount
 .IR /proc ,
-the normal root filesystem and any other file
-systems it has mounted, and then terminates.
+the normal root filesystem and any other filesystems
+it has mounted, and then terminates.
 .IP 6.
 The kernel then mounts the normal root filesystem.
 .IP 7.

man7/cpuset.7

@@ -46,8 +46,8 @@ the administrator can configure the cpusets on a system
 to control the processor and memory placement of processes
 on that system.
 By default, if the cpuset configuration
-on a system is not modified or if the cpuset file
-system is not even mounted, then the cpuset mechanism,
+on a system is not modified or if the cpuset filesystem
+is not even mounted, then the cpuset mechanism,
 though present, has no affect on the system's behavior.
 .PP
 A cpuset defines a list of CPUs and memory nodes.

man7/pipe.7

@@ -45,8 +45,8 @@ processes; see
 .BR pipe (2)
 for an example.
 
-A FIFO (short for First In First Out) has a name within the file
-system (created using
+A FIFO (short for First In First Out) has a name within the filesystem
+(created using
 .BR mkfifo (3)),
 and is opened using
 .BR open (2).