owfs: skip man pages preprocessing

owfs optionally uses soelim with the -r option to process its man pages.
Older versions of groff don't support this option, and we don't care
about documentation on target. So just skip the soelim run.

Fixes:
http://autobuild.buildroot.net/results/bf8/bf893f1ecabb9ecadceb5d56eaa5e4869832e330/
http://autobuild.buildroot.net/results/d36/d369e2c8b90558e84ffd5a44cfe1308111c88637/
http://autobuild.buildroot.net/results/4f3/4f3dfb3cfee1678e6d5da03d09e236d0f4b55b9f/

Cc: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/owfs/owfs.mk

@@ -21,6 +21,9 @@ OWFS_INSTALL_STAGING = YES
 # https://sourceforge.net/p/owfs/support-requests/32/
 OWFS_CONF_OPTS += --disable-owphp --without-php
 
+# Skip man pages processing
+OWFS_CONF_ENV += ac_cv_path_SOELIM=true
+
 ifeq ($(BR2_PACKAGE_LIBFUSE),y)
 OWFS_DEPENDENCIES += libfuse
 OWFS_CONF_OPTS += \