package/ecryptfs-utils: fix build failure without pod2man

Set ac_cv_path_POD2MAN to true to avoid the following build failure:

checking for pod2man... no
configure: error: I couldn't find pod2man; make sure it's installed and in your path

Fixes:
 - http://autobuild.buildroot.org/results/7a3a182aa91a07a720a02f854c59f952930708e1

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/ecryptfs-utils/ecryptfs-utils.mk

@@ -15,6 +15,7 @@ ECRYPTFS_UTILS_CONF_OPTS = --disable-pywrap
 
 #Needed for build system to find pk11func.h and libnss3.so
 ECRYPTFS_UTILS_CONF_ENV = \
+	ac_cv_path_POD2MAN=true \
 	NSS_CFLAGS="-I$(STAGING_DIR)/usr/include/nss -I$(STAGING_DIR)/usr/include/nspr" \
 	NSS_LIBS="-lnss3"