Actually add the -x setenv test Makefile, missed in r326499.

X-MFC with:	r326499

cddl/usr.sbin/dtrace/tests/common/env/Makefile

@@ -0,0 +1,30 @@
+# $FreeBSD$
+
+#
+# This Makefile was generated by $srcdir/cddl/usr.sbin/dtrace/tests/tools/genmakefiles.sh.
+#
+
+PACKAGE=	tests
+
+${PACKAGE}FILES= \
+     err.D_PRAGMA_OPTSET.setfromscript.d  \
+     err.D_PRAGMA_OPTSET.unsetfromscript.d  \
+     tst.ld_nolazyload.ksh  \
+     tst.ld_nolazyload.ksh.out  \
+     tst.setenv1.ksh  \
+     tst.setenv1.ksh.out  \
+     tst.setenv2.ksh  \
+     tst.setenv2.ksh.out  \
+     tst.unsetenv1.ksh  \
+     tst.unsetenv1.ksh.out  \
+     tst.unsetenv2.ksh  \
+     tst.unsetenv2.ksh.out  \
+
+TESTEXES= \
+
+
+CFILES= \
+
+
+
+.include "../../dtrace.test.mk"