Fix page cross references

man2/madvise.2

@@ -190,7 +190,7 @@ with constants
 etc.,
 with a behavior close to that described here.
 There is a similar
-.BR posix_fadvise (3)
+.BR posix_fadvise (2)
 for file access.
 
 .BR MADV_REMOVE ,

man2/sigaction.2

@@ -600,6 +600,7 @@ See
 .SH "SEE ALSO"
 .BR kill (1),
 .BR kill (2),
+.BR killpg (2),
 .BR pause (2),
 .BR sigaltstack (2),
 .BR signal (2),
@@ -608,7 +609,6 @@ See
 .BR sigqueue (2),
 .BR sigsuspend (2),
 .BR wait (2),
-.BR killpg (3),
 .BR raise (3),
 .BR siginterrupt (3),
 .BR sigsetops (3),

man2/signal.2

@@ -182,6 +182,7 @@ This is not recommended.
 .BR kill (1),
 .BR alarm (2),
 .BR kill (2),
+.BR killpg (2),
 .BR pause (2),
 .BR sigaction (2),
 .BR sigpending (2),
@@ -189,7 +190,6 @@ This is not recommended.
 .BR sigqueue (2),
 .BR sigsuspend (2),
 .BR bsd_signal (3),
-.BR killpg (3),
 .BR raise (3),
 .BR siginterrupt (3),
 .BR sigsetops (3),

man7/spufs.7

@@ -111,7 +111,7 @@ file are:
 .TP
 .BR read "(2), " pread "(2), " write "(2), " pwrite "(2), " lseek (2)
 These operate as usual, with the exception that
-.BR seek "(2), " write (2)
+.BR lseek "(2), " write (2)
 and
 .BR pwrite (2)
 are not supported beyond the end of the file.