Issue #11888: remove duplicate check for log2 in configure.in.
diff --git a/configure.in b/configure.in
index c6a9437..7e518a0 100644
--- a/configure.in
+++ b/configure.in
@@ -2512,7 +2512,7 @@
futimens futimes \
gai_strerror getgroups getlogin getloadavg getpeername getpgid getpid \
getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \
- initgroups kill killpg lchmod lchown lockf log2 linkat lstat lutimes mbrtowc mkdirat mkfifo \
+ initgroups kill killpg lchmod lchown lockf linkat lstat lutimes mbrtowc mkdirat mkfifo \
mkfifoat mknod mknodat mktime mremap nice openat pathconf pause plock poll \
posix_fallocate posix_fadvise pread \
pthread_init pthread_kill putenv pwrite readlink readlinkat readv realpath renameat \