[PATCH] autoupdate: do not AC_REQUIRE(AC_PROG_CC)

* Autoupdate will convert various AC_PROG_CC_* lines to AC_PROG_CC
surrounded by AC_REQUIRE macro, which is unexpected.  The AC_PROG_CC is
never used in AC_DEFUN.  The problem can be seen when running autoreconf
in verbose mode after autoupdate.

$ autoupdate -f
$ autoreconf -f -i -Wall
[...]
configure.ac:42: error: AC_REQUIRE(): cannot be used outside of an AC_DEFUN'd macro
---
 lib/autoconf/c.m4 | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
index 53fec83..aac45ab 100644
--- a/lib/autoconf/c.m4
+++ b/lib/autoconf/c.m4
@@ -1461,21 +1461,21 @@ dnl preferably extc11.
 # as that'd be incompatible with how Automake redefines AC_PROG_CC.  See
 # <http://lists.gnu.org/archive/html/autoconf/2012-10/msg00048.html>.
 AU_DEFUN([AC_PROG_CC_C89],
-  [AC_REQUIRE([AC_PROG_CC])],
+  [AC_PROG_CC],
   [$0 is obsolete; use AC_PROG_CC]
 )
 
 # AC_PROG_CC_C99
 # --------------
 AU_DEFUN([AC_PROG_CC_C99],
-  [AC_REQUIRE([AC_PROG_CC])],
+  [AC_PROG_CC],
   [$0 is obsolete; use AC_PROG_CC]
 )
 
 # AC_PROG_CC_STDC
 # ---------------
 AU_DEFUN([AC_PROG_CC_STDC],
-  [AC_REQUIRE([AC_PROG_CC])],
+  [AC_PROG_CC],
   [$0 is obsolete; use AC_PROG_CC]
 )
 
-- 
1.8.4