package/exiv2: really disable samples

EXIV2_ENABLE_BUILD_SAMPLES has been renamed into EXIV2_BUILD_SAMPLES
since version 0.27 and
https://github.com/Exiv2/exiv2/commit/60d436c96960fa314e2d12d017440253ce280d51

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

package/exiv2/exiv2.mk

@@ -10,7 +10,7 @@ EXIV2_INSTALL_STAGING = YES
 EXIV2_LICENSE = GPL-2.0+
 EXIV2_LICENSE_FILES = COPYING
 
-EXIV2_CONF_OPTS += -DEXIV2_ENABLE_BUILD_SAMPLES=OFF
+EXIV2_CONF_OPTS += -DEXIV2_BUILD_SAMPLES=OFF
 
 # The following CMake variable disables a TRY_RUN call in the -pthread
 # test which is not allowed when cross-compiling.