Fix line continuation in fuzz/Makefile.in

Add a missing semicolon to prevent "make test" run from the top-level
directory from failing even when all system and unit tests succeed due
to "(cd fuzz && ${MAKE} check)" returning a non-zero exit code.

fuzz/Makefile.in

@@ -30,7 +30,7 @@ dns_name_fromtext_target@EXEEXT@: dns_name_fromtext_target.@O@ main.@O@ ${ISCDEP
 
 check: ${TARGETS}
 	for fuzzer in ${TARGETS}; do \
-		./$${fuzzer} \
+		./$${fuzzer} ; \
 	done
 
 oss-fuzz: ${TARGETS}