Build error for HEAD on amd64

[Paul Goyette <paul%whooppee.com@localhost>]

With sources updated on 2020-07-02 at 14:06:53 UTC, and using

	build.sh -T /build/netbsd-compat/tools/x86_64/amd64 \
		-D /build/netbsd-compat/dest/amd64          \
		-O /build/netbsd-compat/obj/amd64           \
		-R /build/netbsd-compat/release             \
		-V RELEASEMACHINEDIR=amd64                  \
		-V MKDEBUG=yes                              \
		-V MKKDEBUG=yes                             \
		-U -N2 -m amd64 -j1 release


I get:

/build/netbsd-compat/src_ro/external/bsd/dhcpcd/dist/src/logerr.c: In function 'vlogprintf_r':
/build/netbsd-compat/src_ro/external/bsd/dhcpcd/dist/src/logerr.c:120:8: error:unused variable 'err' [-Werror=unused-variable]
  FILE *err;
        ^~~
cc1: all warnings being treated as errors
*** [logerr.o] Error code 1


+--------------------+--------------------------+-----------------------+
| Paul Goyette       | PGP Key fingerprint:     | E-mail addresses:     |
| (Retired)          | FA29 0E3B 35AF E8AE 6651 | paul%whooppee.com@localhost     |
| Software Developer | 0786 F758 55DE 53BA 7731 | pgoyette%netbsd.org@localhost   |
+--------------------+--------------------------+-----------------------+