intro.2, intro.3: Make subsection heading consistent with other intro.? pages

These pages used "Copyright Terms"; the other intro.? pages
used "Copyright Conditions". Make these pages like the others.

Reported-by: Yuri Kozlov <yoray@komyakino.ru>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/intro.2

@@ -24,7 +24,7 @@
 .\"     new _syscall(2) page, and substantially enhanced and rewrote
 .\"     the remaining material on this page.
 .\"
-.TH INTRO 2 2007-10-23 "Linux" "Linux Programmer's Manual"
+.TH INTRO 2 2010-02-03 "Linux" "Linux Programmer's Manual"
 .SH NAME
 intro \- Introduction to system calls
 .SH DESCRIPTION
@@ -77,7 +77,7 @@ In this case, the programmer must manually invoke the system call using
 Historically, this was also possible using one of the _syscall macros
 described in
 .BR _syscall (2).
-.SS Authors and Copyright Terms
+.SS Authors and Copyright Conditions
 Look at the header of the manual page source for the author(s) and copyright
 conditions.
 Note that these can be different from page to page!

man3/intro.3

@@ -21,7 +21,7 @@
 .\" the source, must acknowledge the copyright and authors of this work.
 .\"
 .\" 2007-10-23 mtk, Nearly a complete rewrite of the earlier page.
-.TH INTRO 3 2009-02-01 "Linux" "Linux Programmer's Manual"
+.TH INTRO 3 2010-02-03 "Linux" "Linux Programmer's Manual"
 .SH NAME
 intro \- Introduction to library functions
 .SH DESCRIPTION
@@ -85,7 +85,7 @@ and standards to which calls in this section conform.
 See
 .BR standards (7).
 .SH NOTES
-.SS Authors and Copyright Terms
+.SS Authors and Copyright Conditions
 Look at the header of the manual page source for the author(s) and copyright
 conditions.
 Note that these can be different from page to page!