CURL_CHECK_FUNC_RECVFROM: android/bionic fix

recvfrom in bionic (the android libc) deviates from POSIX and uses a
const in the 5th argument ("const struct sockaddr *") so the check now
tests for that as well.

acinclude.m4

@@ -5,7 +5,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1998 - 2010, Daniel Stenberg, <daniel@haxx.se>, et al.
+# Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
 #
 # This software is licensed as described in the file COPYING, which
 # you should have received as part of this distribution. The terms
@@ -1663,7 +1663,7 @@ AC_DEFUN([CURL_CHECK_FUNC_RECVFROM], [
           for recvfrom_arg2 in 'char *' 'void *'; do
             for recvfrom_arg3 in 'size_t' 'int' 'socklen_t' 'unsigned int'; do
               for recvfrom_arg4 in 'int' 'unsigned int'; do
-                for recvfrom_arg5 in 'struct sockaddr *' 'void *'; do
+                for recvfrom_arg5 in 'const struct sockaddr *' 'struct sockaddr *' 'void *'; do
                   for recvfrom_arg6 in 'socklen_t *' 'int *' 'unsigned int *' 'size_t *' 'void *'; do
                     if test "$curl_cv_func_recvfrom_args" = "unknown"; then
                       AC_COMPILE_IFELSE([