sapi/fpm/config.m4: check for libapparmor's aa_change_profile()

The fpm code actually uses aa_change_profile(), not change_hat(). Test
for the correct function. (libapparmor always has both, so this is just
a correctness fix.)

Closes GH-6037.

Author: kees

sapi/fpm/config.m4

@@ -571,7 +571,7 @@ if test "$PHP_FPM" != "no"; then
 
   if test "x$PHP_FPM_APPARMOR" != "xno" ; then
     AC_CHECK_HEADERS([sys/apparmor.h])
-    AC_CHECK_LIB(apparmor, change_hat, [
+    AC_CHECK_LIB(apparmor, aa_change_profile, [
       PHP_ADD_LIBRARY(apparmor)
       AC_DEFINE(HAVE_APPARMOR, 1, [ AppArmor confinement available ])
     ],[