package/xz: avoid cicular dependency on autoconf for host builds

autoconf has an implicit dependency on HOST_XZ due to extracting a
tar.xz archive. By enabling XZ_AUTORECONF we create a reverse dependency
for xz on autoconf. This is fine for target builds, but it won't work
for host builds, as the two packages now depend on each other.

This problem only occurs if host tools are being built by Buildroot. If
the build relies on host tools provided by the distro, there is no
circular dependency problem.

Fixes:
4703a7ae9176 package/xz: fix musl static build

Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/xz/xz.mk

@@ -68,5 +68,14 @@ HOST_XZ_CONF_ENV = \
 	CC="$(HOSTCC_NOCCACHE)" \
 	CXX="$(HOSTCXX_NOCCACHE)"
 
+# We need to prevent XZ_AUTORECONF for host builds or we end up with a
+# circular dependency. Since the autoconf build needs to extract a
+# tar.xz archive, autoconf has an implicit dependency on HOST_XZ. By
+# enabling XZ_AUTORECONF we also make host-xz depend on autoconf,
+# which we can't do. It is also not necessary as we're autoreconfuring
+# the target package to fix static build with musl, which is
+# irrelevant for the host package.
+HOST_XZ_AUTORECONF = NO
+
 $(eval $(autotools-package))
 $(eval $(host-autotools-package))