Don't clutter build logs.
Index: configure
--- configure.orig
+++ configure
@@ -21035,7 +21035,6 @@ fi
                      -Wcast-qual \
                      -Wextra \
                      -Wpointer-arith \
-                     -Wredundant-decls \
                      -Wreturn-type \
                      -Wshadow \
                      -Wsign-compare \
@@ -22139,7 +22138,7 @@ fi
 if test -z "${ATF_TARGET_OS}"; then
     { printf '%s\n' "$as_me:${as_lineno-$LINENO}: Checking target OS" >&5
 printf '%s\n' "$as_me: Checking target OS" >&6;}
-    ATF_TARGET_OS="$(uname -o)"
+    ATF_TARGET_OS="$(uname -s)"
 fi
 
  if test "${ATF_TARGET_OS}" = "FreeBSD"; then
